Lake Vištytis is a lake on the border between Lithuania and Russia, near the tripoint with Poland.
The small Lithuanian town of Vištytis on the northern shore was named after the lake. In the west, the extended Romincka Forest stretches along the Russian-Polish border. On the Lithuanian side, the lake and its environs are part of a protected area named Vištytis Regional Park. The lake has 15 inflows, but only one river, the Pissa, tributary to Pregolya, flows from this lake.Lake Vištytis covers an area of 17.83 km2, of which 5.44 km2 belongs to Lithuania.
Wikipedia https://en.wikipedia.org/wiki/Vištytis_(lake)
Address Russia
Coordinates 54°25'29.549" N 22°43'44.457" E