Lake Saroma, or Lake Sarukan, is a lagoon on the coast of Okhotsk in Hokkaido, Japan, across Kitami City, Saroma Town, Toro County, and Yubetsu Town, Monbetsu County. With an area of about 152km², it is the largest lake in Hokkaido, the third largest lake in Japan, and the largest soda lake in Japan. The name of the lake comes from "sar-oma-to" in Ainu language. The word originally referred to the Saromabetsu River that flows into Lake Saroma, but later became the name of the lake.
A big lake, like the sea, is actually a lagoon, also called Lake Saloma