7. Chudskoye LakePskov Oblast Lake Peipus , the largest transboundary lake in Europe, lies on the border between Estonia and Russia. The lake is the fifth-largest in Europe after Lake Ladoga and Lake Onega , Lake Vänern , and Lake Saimaa . Lake Peipus represents a remnant of a body of water which existed in this area during an Ice Age. It covers 3,555 km2 , and has an average depth of 7.1 m , the deepest point being 15 m . The lake has several islands and consists of 3 parts: Lake Peipsi/Chudskoe , the northern part of the lake, with an area of 2,611 km2 Lake Pskov , the southern part of the lake Lake Lämmijärv/Teploe , the sound connecting the other two parts of the lake The lake is used for fishing and recreation, but suffered from some environmental degradation from Soviet-era agriculture. Some 30 rivers and stre... From Wikipedia, the free encyclopedia.