Rivenstone is a submerged mountain within the Broken Bay region of the Lands of the Linnorm Kings that causes great trouble to passing ships. Rivenstone rises up from the depth of one of the deepest valleys of the Steaming Sea, splitting on its way up into seven separate peaks. The highest two peaks reach just below the sea's surface except at the lowest tides when they poke above the tideline; they are known to local sailors but seem to have a knack for sinking visiting ships. Another danger is the presence of a Dagon-worshipping tribe of gutaki: intelligent devilfish. They are led by a cabal of a dozen priests, a mix of clerics and oracles, who use charmed giant octopuses and squid to bolster their tribe making them one of the deadliest threats to dwell within Broken Bay.
- Matthew Goodall, Jonathan Keith, Colin McComb, and Rob McCreary. (2011). Lands of the Linnorm Kings, p. Inside Front Cover. Paizo Publishing, LLC. ISBN 978-1-60125-365-1
- Matthew Goodall, Jonathan Keith, Colin McComb, and Rob McCreary. (2011). Lands of the Linnorm Kings, p. 7f. Paizo Publishing, LLC. ISBN 978-1-60125-365-1