Volcanic Hot Springs is a real time commitment — fit it in only if it's a priority.
Allow 30–45 min (within a trip).
A novelty more than a spa: the water is warmer than the sea and the rust-red minerals supposedly do your skin good, and it's fun to swim into a volcanic cove. The catch is that it's often only a couple of degrees warm, murky, and can stain swimwear orange. Pleasant as part of a wider boat trip, not a destination on its own.