The river Voidomatis springs from the heart of the National Nature Reserve of Vikos. The springs which gush the gully of the gorges and the crystal waters which desire from the melting of the underground glaciers of the mountain Timfi.

Its waters, after crossing the northwestern part of the gorge come out in the plains of Konitsa and meet with the waters of the river Aoos. Its length which overpasses the 15 kilometres and the name which comes from (according to the must prevalent interpretation) from the Slavic VODA-MAT (voda = water)

Voidomatis is considered one of the cleanest rivers in Europe and its water is potable. As it crosses one the most impressive mountainous areas of Greece, along it you meat two one-arched bridges. The bridge of Papigo is the first bridge which was built in Greece with reinforced concrete in 1922 and was founded by donations of Papigo residents.