Descend into a hidden world beneath Grotto Bay Beach Resort's tropical gardens. Prospero's Cave and Cathedral Cave are a pair of ancient underground grottos, each with an electric-blue subterranean lake. Both caves are lit from within to illuminate the spectacular rock formations. The pool in Cathedral Cave is up to 10-metres/30-feet deep in parts, and visitors can take a swim in the cool waters. Prospero’s Cave is home to Grotto Bay’s Natura Spa, offering massages and treatments beneath the dramatic stalactites. The resort organises regular cave tours for interested guests.