Lake Mainit

Lake Mainit is an oligotrophic lake in Mindanao. It is the fourth largest lake in the Philippines, having a surface area of 170.6 square kilometers (65.9 sq mi). The lake is also the deepest lake in the country with maximum depth reaching 223 meters (732 ft). It is located in the northeastern section of Mindanao and shared between the provinces of Surigao del Norte and Agusan del Norte.