Riku is a large volcanic island off the north-east coast of Bamal. Most of the island is covered in dense jungle. The volcano is still active, and has erupted twice during the Firsts’ lifetimes. There is a lot of geothermal activity on the island, including sulfur and mud pits are common on the west side of the island, and the hot springs on the east are well known and thought to have healing properties. At the top of the volcano sits the largest temple to Fire-Bringer.

The island is connected to Bamal by a land bridge only accessible when two of the Four Sisters are aligned. The Rana-suri allow pilgrims wishing to worship Fire-Bringer at the temple to visit their outlying warrens and travel the road to the temple, but few visitors are allowed to enter the central warrens.