Danau Batur, the largest lake on Bali, lies at the foot of Gunung Batur (Mount Batur, 1,717m). Gunung Batur is an active volcano which has erupted more than 20 times in the last few hundred years. The visible lava field was the result of a major eruption in 1963.
The volcano sits at the centre of an enormous caldera, 10km by 13km, left over from the cataclysmic eruption of an old 4,000m high volcano. The rim can be seen bordering the lake in the background.