Lots of boats allow you to visit the grotte nearby Bonifacio, along with the calanques. The water has wonderful colours, and there is always a guide on the boat giving interesting/funny informations (in French, actually, but probably there are some English tours as well). The view of the citadel from the sea is wonderful.
- Bonifacio, the walk of the beaches
- Bonifacio, the medieval citadel: King Aragon steps, cliffs and battlements hike