The Cueva de los Peces ("Cave of the Fish") is a flooded cenote on the eastern shore of the Bay of Pigs, halfway between Playa Larga and Playa Girón. The pool at the surface is a circular opening about 15 metres across, ringed by limestone and overhanging trees; below the surface it drops as a deep blue shaft into a system of submerged caves.
The cenote is open to swimmers and freedivers — entry is unrestricted, the water is fresh, cool and full of small reef fish that have somehow colonised the pool. Scuba divers with cave training can descend further into the system. The site has a basic restaurant, palapas for shade, and a short trail across the road to the open sea, where the snorkelling along the drop-off is excellent. Bring a snorkel and mask.