Lake Lanao or Ranaw is located in Lanao del Sur province, Mindanao, southern Philippines. With a surface area of 340 km². (131 square miles), it is known as the largest lake in Mindanao, and the second largest lake in the Philippines.
Lake Lanao is also considered as one of the 15 ancient lakes in the world. Formed by the tectonic-volcanic damming of a basin between two mountain ranges and the collapse of a large volcano, Lake Lanao has a maximum depth of 112 meters, and an average depth of around 60.3 meters.
Four rivers feed the lake its only outlet is the Agus River, which flows southwest into Iligan Bay via two channels, one over the Maria Cristina Falls and the other over the Linamon Falls. A hydroelectric plant installed on the Lanao Lake and Agus River system generates 70% of the electricity used by the people of Mindanao.
Mabuhay ang Lake Lanao!