The lava comes from the volcanoesNyamuragira and Nyiragongo, 25 km northwest, and numerous smaller volcanic cones which are fed by fissures from these volcanoes. A number of cones can be seen in satellite photographs 7–8 km east of Sake. They also show that lava flows in recent years have covered parts of the road to Goma (National Road No. 2) and have reached the lake, cutting off the bay in which Sake is located, to form a small lake of less than 1 square km. The adjacent bay, which is about 40 km² in size, has almost been cut off by the lava and only a 160 m wide channel remains to connect it to the main body of Lake Kivu.