These four caves, 2km from the town centre along the road to Gisenyi, were created when different lava flows joined to create the Albertine Rift Valley. Bat roosts are a significant feature of the caves, as are huge roof collapses that create vast arrays of coloured light shafts.
Unfortunately, few people visit the caves due to the high entry price, which includes a compulsory guide. Buy the entry ticket from the RDB office in Musanze.