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 . Vikos–Aoös National Park supports a wide diversity of fauna, 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.
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. with a southeast–northwest direction. 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. 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–, 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. 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. 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. It is characterized by the great number of secondary gullies and currents, 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.
Mt Tymphe
thumb|300px|Drakolimni (Dragonlake), overlooked by Ploskos (center) and Astraka (right) peaks|alt=A small lake surrounded by alpine pasture with traces of snow and two mountain peaks in the background: center and right.
Between the two gorges lies the Tymphe mountain range. Its highest peaks are Gamila , Astraka , Ploskos , and Lapatos . 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.
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. Extended glacial conditions prevailed on the uplands of Mt Tymphe during the Late Quaternary period, ca. 28,000 years ago. Additional forms of glacial deposits, which extend down to above sea level, include rock glaciers and limestone pavements.
thumb|left|The village of [[Monodendri (Ioannina)|Monodendri, in dense vegetation. Part of the Vikos Gorge is visible in the background|alt=A small village in the middle of dense vegetation. Part of a deep gorge can be seen on the background.]]
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. 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.
The economic affluence of Zagori's past is still reflected in the architecture of the villages, Sixteen of these stone bridges and seven churches in the region have been listed as protected historical monuments.
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 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.