Voidomatis (also known as “Vikos River”) is a river of the prefecture of Ioannina, a tributary of Aoos. Its main sources are under the village of Vikos. In the course it receives other water streams formed on the slopes of Tymphi or they come from the Vikos Gorge and eventually contribute to Aoos near Konitsa. The river has a total length of 15 km. The name of Voidomatis originates from the Slavic words water (= water) and mati (= source), and not from the established phytophythmology beef, ie ox and eye (pending eye).
Voidomatis is characterized as one of the cleanest rivers in Europe, as it does not face pollution problems. It crosses one of the most beautiful mountainous locations in Greece, which has been designated a national park since 1973, and the gorge of Vikos, which is a monument of natural beauty. Along Voidomatis are some of the most beautiful monotonous, Epirus bridges. The most famous is the bridge of Kleidonia (or Kleidoniavistas), which is located at the exit of the Vikos gorge. Voidomatis is a suitable river for various river sports, such as canoeing and rafting. The temperature of the river water is very low even in the summer months.