Morské oko (Slovakia)

Morské oko is a lake in the Vihorlat Mountains in eastern Slovakia. It is the largest non karst lake and the third biggest natural lake in Slovakia. It is at an altitude of 618 m, covers 0.13 km² with a maximum depth of 25.1 m. It is drained by the river Okna.
The oldest known description of the lake can be found on two maps, dating back to 1687. The earliest official name of the lake known as Blatné jazero dates back to 1784. The name Veľké Vihorlatské jazero was introduced in 1933.
The lake itself is a natural home to 8 species of fish. The native species consist of the brown trout, common minnow and stone loach. In the past, rainbow trout was introduced into the lake, but the prevailing species today is the common chub.
It is a national nature reserve since 1984 and part of the Vihorlat Protected Landscape Area.