Lake Tritriva is a volcanic lake in southwest-central Madagascar, in the region of Vàkinankàratra, located near the village of Belazao. The lake fills an extinct crater in a region notable also for the presence of many hot springs. It sits in the vent of an oval volcanic cone enclosed in vertical gneiss cliffs. The rim of the cone is about 2,000 m (6,600 ft) above sea level, while the surface of the lake is approximately 50 m (160 ft) below the rim. The lake's water level drops during the rainy season and rises when the monsoon rains have ceased.