Have you ever been to an underwater museum? There is one at the ocean bottom near Cancun. Museo Subacuatico de Arte, also known as MUSA, counts 400 life-sized figures scattered across the vast area. Wrecks and reefs conceal a great variety of fish as well. Turtles love to hang out here during their nesting season, which is included in diving season. The seabed is studded with bright starfish, and seemingly threatening manta rays. It says "seemingly," for they are dormant, and hence harmless during diving season. The area is also known for whale sharks, and nocturnal nurse sharks—naturally best observed in a night dive. The best diving and snorkelling conditions are available between March and August.