The Vikos–Aoös National Park () is a national park in the region of Epirus in northwestern Greece. The park, founded in 1973, is one of ten national parks in mainland Greece and is located north of the city of Ioannina in the northern part of the Pindus mountain range. It is named after the two major gorges of the area and encompasses of mountainous terrain, with numerous rivers, lakes, caves, deep canyons, dense coniferous and deciduous forest. The park is part of the Natura 2000 ecological network and one of UNESCO Geoparks and spans an elevation range from . Over 100,000 people visit the park each year and take part in activities including rafting, canoe-kayaking, hiking and mountain biking.

The core of the park, an area of , comprises the spectacular Vikos Gorge, carved by the Voidomatis river. The gorge's main part is long, which attains a depth of , and has a width ranging from 2500 m to only a few meters at its narrowest part. The Aoös gorge, Mt Tymphe ( at Gamila peak), and a number of traditionally preserved settlements form the park's peripheral zone. The park's remoteness and relatively small human population, combined with the great variation of biotopes and microclimatic conditions favors the existence of a rich variety of flora (1,800 species) in the area.Spanopoulou 2001, p. 16Natura 2000, p. 8 Vikos–Aoös National Park supports a wide diversity of fauna,Amanatidou 2005, p. 28 with a plethora of large mammals such as the brown bear, for which the park is one of the last European strongholds, and a variety of natural habitats and ecosystems that rank it among the most valuable parks for nature conservation in Greece.Papageorgiou 2001, p. 3

The first evidence of human presence in the area is dated between 17,000 and 10,000 years ago. The area of the park has been sparsely populated throughout historical times, however from the 17th to the 19th century the local communities of Zagori acquired an autonomous status, flourished economically due to increased trade, and became a major center of folk medicine. In recent decades, ecotourism is seen as a remedy to the economic decline of heavily depopulated local settlements, while preserving the natural environment and local architecture.

Geography and geology

Vikos Gorge

The Vikos Gorge is located on the southern slopes of Mt Tymphe. Its main part is located between the villages of Vikos and Monodendri and attains a depth of about ,Amanatidou 2005, p. 17 with a southeast–northwest direction. The landscape of the long gorge, which belongs to the park's core zone,Hanlidou, Kokkini 1997, p. 2 presents a diverse relief and is characterized by abrupt changes in altitude. At one point the gorge measures deep and wide from rim to rim, and as a result is listed by the Guinness Book of Records as the deepest canyon in the world in proportion to its width, though some gorge lobbyists contest that claim. Steep slopes and precipitous rocky cliffs dominate in the middle and higher zones respectively. Numerous gullies dissect both sides of the gorge and the weathering action of water down its walls creates extended screes.

The Vikos Gorge has been carved over millions of years by the Voidomatis river, a tributary of the Aoös. The Voidomatis is mostly seasonal, with year-round flow occurring only in the lower part of the gorge.Amanatidou 2005, p. 21 Due to its nature, the area of the gorge is precipitous and impassable most of the year.Natura 2000, p. 10

As the Vikos Gorge is a deep cross section of the mountain, its slopes expose a series of rock formations of various ages. The upper layers, at a depth of 0–, consist of relatively young Eocene limestone, at a depth of – they consist of a stratum from the Campanian era, while below they consist of Jurassic and Cretaceous limestone. In the deepest layers, grey Jurassic dolomite is dominant. Sedimentary and lithological investigation in the Voidomatis basin revealed that the innermost alluvial deposits consist of limestone-derived material, carried by the Voidomatis river from higher elevations by glacial action about 30,000 years ago. The subsequent (middle) deposits are the product of de-glaciation and the extended run-off from the uplands about 20,000 years ago, while the outer unit is attributed to human activities associated with pastoralism, which caused extended deforestation and soil erosion.Amanatidou p. 32 The Voidomatis basin contains evidence for three major phases of glaciation, with the two largest and earliest taking place during the Middle Pleistocene.Woodward, Hamlin, Macklin, Hughes, Lewin 2008, p. 64 The final phase of glacial activity probably occurred during the Last Glacial Maximum, between 22,000 and 20,000 ago.

A special feature of the limestone, resulting from its weathering by water, is its karstic nature.Amanatidou 2005, pp. 21–22 During the large Middle Pleistocene glaciations, surface runoff from glacial meltwaters would have fed directly into the river channel network because much of the upland limestone terrain was covered by ice, and many conduits in the karst would have been choked with sediment or permanently frozen. As a result, the glacier snouts came close to the modern valley bottoms. In contrast, during interglacial and interstadial periods, more effective coupling occurred between the surface drainage network and the internal karst drainage system.Woodward, Hamlin, Macklin, Hughes, Lewin 2008, p. 63 Since limestone dissolves as the water percolates through its pores, an extended underground drainage system has developed, with caves and channels that enlarge with time when their roofs collapse, producing rocky exposures and perpendicular slopes, which is also the reason why the water is scarce. Only when an impenetrable stratum is met, does water appear on the surface.

Aoös Gorge In the northern part of the Park, and very close to the town of Konitsa, the Aoös river passes through channels formed by the bulges of the nearby mountains of Trapezitsa , Mt Tymphe and Raidovouni , creating the Aoös Gorge that is long. It has an east–west direction and features numerous stone single-arched bridges from the 17th to 19th centuries, as well as monasteries built in the local architectural style.Papadopoulou 2008, p. 12, 18, 20 It is characterized by the great number of secondary gullies and currents, while the southern part of the gorge is steeper than the northern part. Deep and steep ravines within the perpendicular walls carry down into the Aoös large quantities of material resulting from limestone-weathering.Paschos, Nikolaou, Papanikos 2004, p. 18 The compact dolomites that lie on the bottom of the gorge date to the Early Jurassic period and are the oldest rock formations in the Park. Their age has been determined by means of sea fossils found inside them.Paschos, Nikolaou, Papanikos 2004, p. 7

Mt Tymphe

Between the two gorges lies the Tymphe mountain range. Its highest peaks are Gamila , Astraka , Ploskos , and Lapatos . A unique feature of this area is natural pools formed by the erosion of local stream beds. A number of alpine lakes are found in the high-altitude zone of Mt Tymphe, surrounded by alpine pasture, which are home to several rare amphibian species. The biggest lake of the National Park, Drakolimni ("Dragonlake"), a formation that was created after the retreat of the glaciers,Paschos, Nikolaou, Papanikos 2004, p. 15 is located at a height of on Mt Tymphe. Its maximum depth is , while its surface covers .

A number of vertical caves and precipices are found in the area around the village of Papingo, which lies near the Gamila and Astraka peaks. Some of them bear names inspired from mythology, such as the Hole of Odysseus and Chasm of Epos. These are being studied and explored by caving enthusiasts. The cave of "Provatina" ("Ewe's Cave"), with a depth of , one of the deepest worldwide, was first discovered in 1965 by British speleologists of the Cambridge University Caving Club, and has since then been surveyed by a large number of expeditions. The nearby Chasm of Epos, with a depth of , drains the water coming from the surrounding plateaus.Paschos, Nikolaou, Papanikos 2004, p. 16

Mt Tymphe represents a series of uplifted fault blocks and faulted escarpments and is largely composed of Palaeocene-Eocene limestone, with some exposures of Campanian-Jurassic dolomite and limestone on the northern scarp. The lower slopes are dominated by younger flysch rocks, which consist of thin beds of graded sandstones intercalated with softer, fissile siltstones.Hughes, Gibbard, Woodward 2003, p. 2 Extended glacial conditions prevailed on the uplands of Mt Tymphe during the Late Quaternary period, ca. 28,000 years ago. The glacial landscape is well-developed, especially on the southern slopes of Mt Tymphe, across the Astraka-Gamila plateau, and in the upland terrain above the villages of Skamneli and Tsepelovo, where lateral and terminal moraines form major landscape features.Woodward, Hamlin, Macklin, Hughes, Lewin 2008, p. 8 Additional forms of glacial deposits, which extend down to above sea level,Hughes, Gibbard, Woodward 2003, p. 3 include rock glaciers and limestone pavements.Woodward, Hamlin, Macklin, Hughes, Lewin 2008, p. 49

Settlements There are four villages inside the Vikos–Aoös National Park, and an additional nine near the borders of the peripheral zone. All of these settlements, in the western part of the Zagori region, are sparsely populated with a total population of 1,515 people. The villages have a nucleus-like form, with the houses situated around the central square and interconnected by pathways paved by slate or cobblestone.Amanatidou 2005, p. 36 Historically, all the villages of the Zagori region were connected by a system of paths or small roads and they functioned more like a single entity rather than as separate communities.Vokou, Katradia, Kokkini 1993, p. 8

The economic affluence of Zagori's past is still reflected in the architecture of the villages, while today the preservation of the local architectural legacy is enshrined in a law which dictates that all buildings in the area must be constructed with local traditional materials and in compliance with local architecture. One of the characteristic features of the National Park is its stone bridges, which were the only connection to the outside world until roads were built in the 1950s.Drakopoulou 2004, p. 27 Sixteen of these stone bridges and seven churches in the region have been listed as protected historical monuments.Spanopoulou 2001, p. 17

Climate The climate of the Vikos–Aoös National Park is Mediterranean, transitioning to continental. The Mediterranean character is characterized by the annual distribution of precipitation, high in the winter months and experiencing a drought period of two to three months in summer. The continental climatic element is attributed to the high amplitude of annual temperature variation, to such a degree that the difference between mean maximum and mean minimum annual temperature, exceeds . The climate of the area is quite unique due to the complex relief, variation in altitude, and the position of the area with regard to the Ionian Sea coastline.Paschos, Nikolaou, Papanikos 2004, p. 5 The mean annual temperature and annual precipitation are and respectively. Extremely low temperatures occur in the area during the winter months. Compared to Mediterranean bioclimatic divisions, the area belongs to the humid zone with cold winters.Amanatidou 2005, pp. 23–24

Wildlife