The Voïdomatis ('Good Water' in its Slavic roots) River, a tributary of the Aoös, carved the 12km-long, 900m-deep Vikos Gorge over millions of years. Per Guinness, it’s the world’s deepest canyon in proportion to its width. The cliffs begin near Vitsa and run north to near Papingo; the river's springs are below the village of Vikos, where there is also an impressive viewpoint. Several other overlooks on either side of the gorge are accessible by short trails.
The gorge and the Tymfi mountain range to the northwest comprise a special protected zone called the Vikos-Aoös Geopark, itself part of the much larger Northern Pindos National Park. Hiking routes around and in the gorge are mostly well tended and blazed; get guidance for your experience level from EOS in Ioannina. The most typical, if quite challenging, route starts in Monodendri, where a steep path heads down; at canyon's end, a right-hand trail leads to Mikro Papingo; the walk takes more than six hours. The only water is at Klima Spring, halfway along the gorge. Check the weather forecast and kit yourself out with sturdy hiking boots and drinking water. Always let someone local (such as your guesthouse) know your departure time and planned route, so they can raise the alarm if necessary.