Lake Peipus the town. Near Kallaste, there is one of the largest surfacings of Devonian sandstone with a length of and a maximum height of , as well as several caves and one of the largest colonies of swallows in Estonia. Lake Peipus Lake Peipus (; ; ) is 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 (in Russia north of St. Petersburg), Lake Vänern (in Sweden), and Lake Saimaa (in Finland). Lake Peipus represents a remnant of a body of water which
Onega River Monastery on an island in the Lake Kozheozero. Some of the finest monuments of the northern wooden architecture are located in the basin of the Onega, including ensembles of Lyadiny, Saunino Pogost, Krasnaya Lyaga, and Bolzhaya Shalga. These monuments also suffer from the lack of protection and their number steadily diminishes. In fact, the majority of them have been lost. The river splits into the Big Onega and Little Onega Rivers from its estuary, but then these branches join again, forming a big flat island. It freezes up in late October - early December and stays under the ice until