The arcuate lake in the center of this NASA Landsat image (with north to the top) is Lake Leonard. The lake partially fills a 4 x 5 km caldera cutting this andesitic-to-dacitic stratovolcano complex in the Leonard Range in SE Mindanao Island. Activity at the Leonard Range dates back to the Pleistocene, but explosive eruptions continued well into the Holocene, with the latest dated eruption taking place about 1800 years ago. Active geothermal areas are found both north and south of the volcano. NASA Landsat7 image (worldwind.arc.nasa.gov)