One of the largest natural lakes in our country, Vegoritida, although it has undergone significant alterations from human activities. Vegoritida is also referred to as Lake Ostrovo, while its other three names are Lake Arnissa, Lake Kelly and Lake St. Panteleimon. It is located on the borders of the prefectures of Pella, Florina and Kozani and is surrounded by the mountains Voras in the north, Vermio in the east and only 2.5 km to the east of the lake Petron. Vegoritida is the lowest point of the lake of Zazaris, Chimaditida and Petronas, from which it is supplied with water through a system of canals and canals, and there are also four large streams: the Gorge, Pentavrysos, Agios Athanasios and Arnistas. The catchment area of the lake reaches 911 sq. Km.
Vegoritida is an important biotope for many bird species and together with Lake Petron is an almost unified ecosystem.