Lake Bruin is an ox-bow lake of the Mississippi River located in Tensas Parish in northeastern Louisiana. It consists of some 3,000 acres (12 km²) of unusually clear water, particularly suited for swimming, boating, and fishing. Part of the lake is owned by the state, which operates Lake Bruin State Park, one of nineteen Louisiana state parks. Much of the land beside the lake is in private hands, and many fashionable homes, both vacation houses and permanent residences, have been constructed there in recent years.