Lake Mainit is the fourth largest lake in the Philippines, having a surface area of 173.40 square kilometres (66.95 sq mi). The lake is also the deepest lake in the country with maximum depth reaching 223 metres (732 ft). It is located in the northeastern section of Mindanao and shared between the provinces of Surigao del Norte and Agusan del Norte.
The Lake Mainit Development Alliance (LMDA) is an alliance of municipalities or local government units, government line agencies and civil society organizations in Lake Mainit area. Its significant role is to serve as the coordinating body of multi stakeholders in preserving and promoting Lake Mainit ecosystem.