Derinöz Canyon lies within the boundaries of Suluova, the district to the west of Amasya, on the slopes of Akdağ that face Suluova, a mountain long regarded as the greatest in the province. About four kilometres long, this natural cleft is a narrow passage whose width falls to as little as one metre in places and whose walls rise forty to fifty metres. Together with Kızkayası near Merzifon it is one of the most frequently mentioned of Amasya's canyons, and it is usually presented as a route for nature walking, with stretches where one has to wade through the water. In the lists of Turkish canyons compiled by canyoning researchers it appears as "Derinöz (Ümmet Deresi) Canyon", an entry that also preserves the local name of the stream that cut the gorge.

Although no detailed scientific study has been devoted to the canyon itself, the mountain in which it lies has attracted geologists and botanists in recent years. The rock make-up of Akdağ, the Derinöz fault line that separates the mountain from its neighbour Karaömer Dağı and takes its name from this very area, the formation of the Suluova plain, and the floristic surveys that have recorded more than seven hundred plant taxa on the mountain all help to explain the setting in which the canyon took shape. The older written sources, for their part, describe Akdağ and Suluova through different eyes, with their summer pastures, their flocks and their rivers.

Location and Surroundings

Suluova stands about twenty-five kilometres west of Amasya, on the edge of a broad plain that runs into the Merzifon plain. The district covers 516 square kilometres and lies at an altitude of 510 metres. It is ringed on three sides by mountains of modest height, the highest of which is Akdağ, rising to 2,064 metres to the south-east of the district. From the foothills up to the higher ground the vegetation is forest of pine, hornbeam and oak; down on the plain it gives way to orchards, poplars and willows. Derinöz Canyon opened in the transitional belt between this mountain and the plain, at the point where water begins its descent from the heights to the lowland.

The canyon lies in the neighbourhood of Seyfe, a village belonging to Suluova. Among the places where they gathered specimens, the researchers who studied the flora of Akdağ list "Seyfe village, around Derinöz Dam", a forest dominated by Anatolian black pine at about 1,150 metres. The same list includes streamside vegetation at 1,250 metres between the villages of Seyfe and Karakese, steppe slopes rising to 1,750 metres between Seyfe and Aktaş, more black pine forest at 1,110 metres in the nearby Kapaklı recreation area, Turkey oak around Derebaşalan, and oriental beech forest at 1,500 metres between the villages of Soku and Kuzalan. These steps in altitude show that a walk of a few hours in and around the canyon can pass through plant communities that differ greatly from one another. A short nature trail through the forest towards Seyfe, suitable also for families with children, is described as well.

The Stream That Cut the Canyon and the Tersakan Basin

The water system of the area is important for understanding the canyon. The district's official descriptions name the Tersakan Çayı as Suluova's most important stream; it enters the district at Eski Çeltek, curves across the plain and joins the Yeşilırmak at Amasya. The same descriptions give the Derinöz Çayı as the source of the Tersakan. On this stream, near the village of Seyfe, stands the Derinöz Dam, completed in 2003, which irrigates an area of 6,500 hectares. Some lists based on the records of the State Hydraulic Works place the dam within Samsun Province and date its construction to 1990-2002; the fact that the provincial boundary between Suluova and Lâdik runs through this area may account for the difference, but exactly which province the dam lies in could not be established with certainty.

Older and newer accounts differ on the source of the Tersakan. Describing the district of Lâdik, Hüseyin Hüsâmeddîn Yasar mentions a large lake some ten kilometres east of the town, about six kilometres long, three kilometres wide and some six metres deep. Six streams coming down from the Seki, Kızoğlu, Polad and Çakır Gümüş summer pastures flow into this lake, and the water leaving it forms the river known as the "Tersakan". Some present-day descriptions likewise define the Tersakan as a stream rising from Lake Lâdik. On this reading the Derinöz Çayı should be thought of as one of the branches that come down the slopes of Akdağ to feed the Tersakan system, rather than as the river's single source. That the stream which cut the canyon is called Derinöz in one source and Ümmet Deresi in another likewise shows how the same water network is divided into segments under local names; whether the two names belong to different stretches of the same watercourse could not be determined.

What Hüsâmeddîn records about the Tersakan also describes the former state of the river into which the canyon's water flows. According to the author, the river was called "Tersakan", the "backward-flowing", because it runs from north to south, and Arabic sources record it as "al-Nahr al-Maqlub", the overturned river; older documents give the names "Astifonos" and "İstiyotos". Flowing from the north of Lâdik, the river passes east of Havza and through the middle of Suluova, enters the northern gorge of Amasya and pours into the Yeşilırmak above Bahçeler İçi. Its flow is constant, falling in summer and rising in spring; because it overflows and causes damage when in spate, people also call it "Deliçay", the mad stream. The mills, vineyards and gardens along its two banks draw on its water. Over it stand the Ziyare Bridge, regarded as a Seljuk work, and the single-arched Çeltek Bridge at the far end of Suluova, where the Amasya and Merzifon roads part, which is known to have existed in 812 (1409-1410). Hüsâmeddîn also suggests that the ancient river called the Lycus must be the present-day Tersakan. That one of the branches of a river which floods in spring passes through a narrow canyon may be read as an old reminder of why the water level must be watched at Derinöz.

Akdağ and Suluova in the Older Sources

In the Ottoman period the mountain to which the canyon belongs was the best known in Amasya. Hüsâmeddîn names Akdağ as the largest of the mountains in the Sanjak of Amasya and calls Taşan (Tavşan) Dağı, north of Merzifon, the largest after it. One of the four sub-districts (nahiye) of the kaza of Amasya also bore the mountain's name. According to the author, the Akdağ sub-district was so called because it lay at the foot of a mountain long known as "Akdağ", stretching from east to west and rising some twelve hundred metres above the surrounding level ground. Its summer pastures were plentiful, its winter quarters well regarded, its water abundant and its air wholesome; most of the sheep of the liva of Amasya grazed there in summer. The butter, cheese and yoghurt produced there enjoyed, in Hüsâmeddîn's words, an extraordinary fame throughout the land of "Pontus". The town of Lâdik too was built on the northern slopes of the same mountain, on a gentle rise inclining to the south.

The name Suluova also appears in the older records. According to Hüsâmeddîn, the Hakala sub-district, which covered the northern parts of Amasya, was formerly known as "Arguma-Suluova", and after about 745 (1344-1345) the name of the growing village of Hakala came to the fore. Within the same sub-district, on the bank of the Tersakan Çayı, stands the tomb of Abdülganî, one of the Halveti sheikhs; on spring days the area around it filled with people, took on the look of a fair, and not a day passed without a sacrifice. Osman Fevzi Olcay, listing the tombs of saints around Amasya, also gives the location of this tomb as "north of Saygılı village, on the bank of the Tersakan river". Today the picnic ground around the Ganibaba Tomb is one of the places visitors to the canyon can take in on the same day. The foothills of Akdağ also served at times as a refuge: Hüsâmeddîn writes that in 1216 (1802) Kutoğlu Hüseyin Pasha of Amasya, who had been appointed to Erzurum and whose execution had then been ordered, hid in the foothills of Akdağ and, when besieged, surrendered without a fight. On which side of the mountain this took place is not stated.

The Geological Past of the Region

Amasya and its surroundings form part of the Pontide mountain belt that runs along the Black Sea coast, and lie within the Tokat massif, regarded as the eastern extension of the Sakarya continent. According to official geological descriptions, the rock units of the region range from rocks formed some 430 million years ago and later metamorphosed, to the alluvium accumulating on the plains today. The uplift of the Pontides began about 29 million years ago, and with the formation of the North Anatolian Fault and its branches the present appearance of the rivers, plains and mountains took shape. The Suluova, Geldingen, Taşova and Aydınca plains are young basins opened during this process, and alluvium is still being deposited within them.

The more recent past of Akdağ has to do with the sea. According to Suluova's official history, during the Eocene, some 54 to 38 million years ago, the region was covered by a shallow sea. The Alpine movements at the close of that period caused folding and faulting; the rock on which Amasya Castle stands, Akdağ and the Lokman mountains rose to become islands, and once the sea had withdrawn entirely the present topography of the region emerged. The fossil beds on Akdağ are cited as evidence that the area once lay under water. Among the units listed for the region are the Bilecik Limestone, the carbonate limestones of the Amasya Formation, and the Lokman Formation, whose fossils point to a shallow marine environment.

The Limestones of Akdağ and the Derinöz Fault Line

The study of the flora of Akdağ published in 2020 gives two pieces of information important for the canyon when it describes the geography of the mountain. The first concerns its rocks: drawing on the doctoral thesis on the morphotectonic evolution of the Amasya region by the geologist Mehmet Korhan Erturaç, it gives the dominant lithology of Akdağ as Permian blocks of fusulinid limestone. Fusulinids were single-celled organisms that lived in shallow seas some 300 million years ago, and their shells are abundant in limestones. The second concerns the mountain's boundary: to the north-west of Akdağ rises Karaömer Dağı, called its "sister mountain", and the Derinöz fault line, a branch of the North Anatolian fault system, separates the two mountains and forms a natural border between them.

Taken together, these two facts provide a reasonable framework for why the canyon lies where it does. Limestone is a rock in which water, both by wearing it away and by dissolving it, can readily open deep and narrow clefts; fault lines, by fracturing and weakening the rock, often lead streams to find their course along such broken zones. That the name Derinöz survives in the canyon, the fault line and the dam alike shows that these elements are gathered in the same narrow section. Nevertheless, no published field study could be found showing in which rock unit the canyon was cut, whether it follows the fault line directly, or when it began to form; the idea that the canyon was opened by a stream cutting into limestone along the fault therefore remains an inference.

The Formation of the Suluova Basin

The history of the basin that carries the canyon's water to the plain is better known. According to Erturaç's doctoral thesis, the wide area between Amasya, Tokat and Çorum is a wedge-shaped zone of deformation, named the "Amasya Shear Zone", lying between the North Anatolian Fault and the Ezinepazar-Sungurlu Fault System that branches from it. The Suluova Basin, which takes in the Suluova, Merzifon, Gümüşhacıköy and Alıcık plains, is one of the depressions within this zone. The thesis relates that the basin began to form in the Middle Pliocene as a half-graben along a fault on its north-eastern edge, and that this closed basin gradually widened into a large lake, "Lake Suluova".

An article published by the same researcher and his colleagues in 2019, however, places the beginning of the basin at the start of the Quaternary and gives the process in greater detail. According to it, the basin first filled with alluvial fans, and as subsidence progressed a freshwater lake spread across its centre. During the Calabrian, roughly 1.8 to 0.78 million years ago, this broad lake served as a refuge for a rich fauna of large and small land mammals. Towards the onset of the Middle Pleistocene, about 0.79 million years ago, erosion increased across the region and the old Lake Suluova was captured by the surrounding river system and drained. At the same time, east-west right-lateral and north-east to south-west left-lateral faults began to cut across the former basin structure; according to the article these faults are still active today and are the source of earthquakes in the region. Once the lake had drained, the streams coming down from Akdağ would be expected to cut more deeply towards the plain; it is possible that narrow gorges such as Derinöz deepened during this last million years of erosion, but no dating has been carried out for the canyon.

Dimensions and Appearance of the Canyon

The sources largely agree on the canyon's dimensions: about four kilometres long, one metre wide at its narrowest and 45 to 50 metres high in places. Another account gives the height as 40 to 50 metres. The two ranges do not contradict each other; all are approximate figures and show that the walls do not reach the same height everywhere along the canyon. Where the width falls to a metre the walls close in from both sides, and from below only a narrow strip of sky can be seen.

Inside, the canyon is noticeably cooler than the plain around it. Because sunlight reaches the stones on its floor only sparingly, the rock faces and the stones of the bed gather moss in the narrow sections. There are waterfalls along the route, and walkers pass between them. The plants clinging to cracks in the walls and the green cover of the floor set the canyon apart from the dry slopes around it. The contrast becomes sharper when the climate of the area is considered: the Akdağ flora study gives the annual precipitation as 334 millimetres and the mean annual temperature as 10.3 degrees, according to data from the state meteorological station. In surroundings that receive so little rain, a shaded and constantly moist cleft forms a separate habitat for many plants and mosses that cannot hold on to the open slopes. The sources particularly stress the canyon's green spaces and waterfalls and count it among the natural attractions of the province that draw visitors from Turkey and abroad.

Vegetation and Wildlife

Akdağ was recognised as one of Turkey's Important Plant Areas in 2005. The mountain's plants were first collected in the second half of the 1970s by the botanist Kerim Alpınar, who named these specimens in his doctoral thesis entitled "Plants of Amasya (Akdağ)". A considerable part of the localities where specimens were collected for the thesis, however, lay outside the boundaries of the mountain, and the article "New observations on the flora of Amasya and Akdağ" published by Baytop and Alpınar in 1980 did not include a complete plant list either. While studying the mountain's vegetation between 2016 and 2019, Cengiz Yıldırım, Erkan Yalçın and Arzu Cansaran worked together with Alpınar, combining the findings of the two periods to publish a complete list for the mountain in 2020.

That study identified 705 taxa on Akdağ, of which 699 are seed plants and 6 belong to the fern group. In terms of the geographical origin of the species, Euro-Siberian and Irano-Turanian elements predominate; the mountain lies in a transition belt between these two floristic regions, with the Euro-Siberian influence the stronger. In this respect the researchers liken Akdağ to the Karaömer, Sakarat and Tavşan mountains and note that the climatic transition between Central Anatolia and the Black Sea gives rise to a "xero-Euxine" vegetation belt made up of deciduous oak, pine and mixed pine-oak forests. The number of endemic taxa is 74, an endemism rate of 10.49 per cent. Among them are plants in the "vulnerable" threat category, such as Epipactis helleborine subsp. bithynica, a subspecies of orchid, Iris histrioides, an iris species, Astragalus syringus, Alyssum bornmuelleri, Galium bornmuelleri and an alpine variety of Veronica gentianoides. A small-leaved variety of the mountain's wild apple is listed as "data deficient".

The specimens taken around Seyfe, where the canyon lies, give a direct idea of its vegetation. In the black pine forest around the Derinöz Dam, aspen, Lonicera orientalis, one of the wild honeysuckles, and Geum urbanum, known as clove root, were recorded. Along the stream between Seyfe and Karakese, species fond of damp ground were collected, among them white willow, wild mint, the large-leaved butterbur (Petasites hybridus), round-leaved saxifrage (Saxifraga rotundifolia), Lysimachia vulgaris, tamarisk and Valeriana alliariifolia. Whether these species also grow inside the canyon has not been investigated separately, but they reflect the plant community further up the same stream.

The mountain's moss flora has also been studied separately. Between 2009 and 2011 Kerem Canlı and Barbaros Çetin identified 178 moss taxa belonging to 26 families in some 1,500 specimens collected from 37 stations between 227 and 2,040 metres, reporting that 94 of them were recorded for the first time in the A3 square used in plant geography. The researchers stress that although Akdağ was regarded as an Important Plant Area, its mosses had never been studied before. The mosses covering the shaded, wet walls of the canyon are part of this rich community. Besides its plants, the mountain also provides a habitat for threatened mammals such as the lynx, roe deer, wolf and marten. Another study on the plant associations of Akdağ, published by the same research team in 2022, identified thirteen plant associations on the mountain and described three of them as forest and seven as mountain steppe associations new to science.

Walking and Outdoor Sports

Derinöz is used above all for canyon walking. Depending on the season and the rainfall, much of the route is followed through the water itself, passing by waterfalls. When the water is high the walk becomes harder, while in dry periods it is easier to move on by hopping from stone to stone. Walking at Derinöz is therefore less an ordinary footpath stroll than an activity that demands finding one's way between water and rock. Equipment such as shoes that can get wet and have non-slip soles, along with spare clothing, is recommended for this reason. That a sudden downpour can quickly raise the water level in a narrow canyon is also one of the general rules of canyon walking; and since the old records show that the branches of the Tersakan flood in spring, the canyon should not be entered without checking the weather.

For those who want to take photographs, the narrow sections are among the rare places where light falls in a thin strip between the walls. In the lists of Turkish canyons compiled by canyon research associations, which include more than a hundred canyons, two are from Amasya, and Derinöz is one of them. When the most suitable areas for nature-based sports in Amasya are listed, Derinöz, together with Kızkayası, is one of the two places that come to mind for canyon walking. The summer pastures and forest roads around the canyon also allow longer walks towards the higher reaches of Akdağ; on the summit area of the mountain, between about 1,700 and 2,000 metres, there is a television transmitter surrounded by broad grasslands.

Water, the Dam and Access

Access to the canyon is not open at all times. According to one source, the entrances to the canyon have been restricted because Suluova's drinking water is drawn from this area. The district's official description likewise states that its drinking water needs are met by the municipal network bringing water from the Akdağ springs and by the storage facility in the area. The Derinöz Dam further up the stream, meanwhile, was built for irrigation and waters part of the Lâdik and Suluova plains. The presence of both drinking-water sources and a reservoir in the same valley suggests that some sections of the canyon may be kept closed to protect the cleanliness of the water. Before setting out it is necessary to ask the Suluova District Governorship or the Amasya Provincial Directorate of Culture and Tourism about the current situation, since without an official announcement it cannot be said for certain when the conditions of access changed.

Conservation Status

In the media archive of the Ministry of Culture and Tourism the canyon is registered as a nature image contributed by the Amasya Provincial Directorate of Culture and Tourism; the record contains no detailed description. No information could be found that Derinöz has been registered as a nature park, natural monument or natural protected site. The recognition of Akdağ as an Important Plant Area is a scientific assessment and does not in itself confer legal protection. The natural area in the district known to be under legal protection is the Yedikır reservoir; this irrigation reservoir, begun in 1979 and brought into service in 1986, was declared a first-degree natural protected site by a decision of the conservation board attached to the Ministry of Culture dated 17 August 1989. Whether a similar decision has been taken for Derinöz is not known.

Alongside Amasya's Other Canyons

When canyons are mentioned in Amasya, Kızkayası near Merzifon is named together with Derinöz. Kızkayası is about three kilometres long, and its gorge holds a bridge thought to date from the Roman period, remains of a temple, mills and lime kilns, adding a historical layer to its natural beauty. Derinöz, by contrast, is a canyon at the foot of Akdağ that the sources present mainly as a passage through water, and they make no mention of any historic structure within it. The two gorges lie in different districts of the same province, at the foot of different mountains, and offer different experiences.

Besides the canyon, Suluova's natural and cultural stopping places include the Yedi Kuğular (Seven Swans) bird sanctuary around the Yedikır reservoir, the Kapaklı Forest and Recreation Area, the summer pastures on the ridges of Akdağ and the picnic ground around the Ganibaba Tomb. The number of bird species seen at Yedi Kuğular is given differently in the sources: some descriptions speak of more than two hundred species, while the district's official record states that 34 bird species have been identified. The lake lies on a bird migration route and shelters waterfowl in the winter months. If a canyon walk is to be fitted into the same day as these stops, the water level and whether the entrance is open should be checked in advance.

Chronology

About 54-38 million years ago: During the Eocene the region is covered by a shallow sea; with the Alpine movements at the end of the period, Akdağ rises.

About 1.8-0.78 million years ago: A broad freshwater lake occupies the Suluova Basin.

About 0.79 million years ago: The old Lake Suluova is captured by the river system and drains, and erosion increases across the region.

745 (1344-1345): According to Hüsâmeddîn, after this date the sub-district called "Arguma-Suluova" begins to be known by the name of the village of Hakala.

812 (1409-1410): The Çeltek Bridge over the Tersakan is known to have existed by this date.

1216 (1802): Kutoğlu Hüseyin Pasha is besieged in the foothills of Akdağ and surrenders.

1974-1978: Kerim Alpınar makes the first systematic plant collections on Akdağ.

1986: The Yedikır reservoir comes into service; in 1989 it is declared a first-degree natural protected site.

2003: The Derinöz Dam on the Derinöz Çayı is completed (some lists give the construction period as 1990-2002).

2005: Akdağ is included among Turkey's Important Plant Areas.

2009-2011: The moss flora of Akdağ is studied at 37 stations.

2016-2019: Field studies on the vegetation of Akdağ are carried out, published in 2020 with a complete list of 705 taxa.

What Could Not Be Verified

No reliable explanation of the origin of the canyon's name could be found. Some accounts say that the name comes from the canyon's depth and the coolness of its water, but this explanation is not documented; the fact that the same name is also given to the fault line, the stream and the dam in the area suggests that the name belonged to the whole valley before it was attached to the canyon. Under which of the names Derinöz Çayı and Ümmet Deresi the stream that cut the canyon appears in official records, in which rock unit the canyon was cut, whether it follows the Derinöz fault line, and its age of formation could not be determined. The sources consulted also give no information on the total time needed to walk the route, the date from which access restrictions began, or its official conservation status. The completion year of the Derinöz Dam and the province to which it belongs are given differently in different sources.

Bibliography

Primary sources

Academic studies

Official sources

Other sources

Online sources