GOKCHA (Gok-Chai; Armen. Sevanga; anc. Haosravaglia), a lake in Armenia 40° 20' N. and 35' E., altitude 6,345 ft., triangular in shape, measures 45 m. N.W.–S.E., max. width 25 m., max. depth 67 fathoms, area 54o sq.m. It is surrounded by barren mountains of volcanic origin 12,000 ft. high. Its outflow is the Zanga, a tributary of the Aras (Araxes) ; it never freezes, and its level undergoes periodical oscillations. It contains four species of Salmonidae, and two of Cyprinidae, peculiar to the drainage area of this lake. A lava island in it is crowned by an Armenian monastery.