Ranco Lake (Spanish: Lago Ranco) is located in Ranco Province of Chile. It is the largest lake of Los Ríos Region and the fourth largest in Chile. Administratively Ranco Lake is split into three communes; La Unión, Futrono and Lago Ranco. The lake hosts a series of islands, of which Huapi Island is the largest. The western half of the lake is roughly circular while the eastern part features deep embayments.