page_title: Vikos–Aoös National Park
section_title: Vikos Gorge
hierarchical_section_title: Vikos–Aoös National Park / Geography and geology / Vikos Gorge
caption_attribution_description: The Vikos gorge, Vikos-Aoos National Park, Epirus, Greece. Panorama of several photos, ranging approximately 180 degrees.
context_page_description: 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 30 kilometres 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 12,600 hectares 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 550 to 2,497 meters. 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 3,400 hectares, comprises the spectacular Vikos Gorge, carved by the Voidomatis river. The gorge's main part is 12 km long and attains a depth of 1,000 meters. The Aoös gorge, Mt Tymphe, and a number of traditionally preserved settlements form the park's peripheral zone.
context_section_description: 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 1,000 m (3,281 ft), with a southeast-northwest direction.  The landscape of the 20 km (12 mi) long gorge, 12 km (7 mi) which belongs to the park's core zone, presents a diverse relief and is characterized by abrupt changes in altitude.  At one point the gorge measures 900 m (2,953 ft) deep and 1,100 m (3,609 ft) 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. Due to its nature, the area of the gorge is precipitous and impassable most of the year.
  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 0–200 m (660 ft), consist of relatively young Eocene limestone, at a depth of 200 m (660 ft)–700 m (2,300 ft) they consist of a stratum from the Campanian era, while below 700 m (2,300 ft) 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. The Voidomatis basin contains evidence for three major phases of glaciation, with the two largest and earliest taking place during the Middle Pleistocene. 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. 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. 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.
caption: Panoramic view of Vikos Gorge
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