Beneath these glistening bays, a barrier reef runs almost the length, from the Belizean border in the south to the Yucatan peninsula’s north-east tip. Some of the world’s finest dive sites are found around these tropical shores, where you’ll also find majestic Maya ruins at Tulum and inland at Cobá. The Riviera Maya has a whole network of underground cenotes (limestone sinkholes), which you can dive, swim and snorkel in. Playa del Carmen has seen new visitors in recent decades as people have been drawn in by the laid-back lifestyle, perfect climate and beautiful beaches. Cancún was hand-picked in the Seventies as Mexico’s new holiday hotspot, touted as an alternative to loco Acapulco. The one-time undeveloped sand spit now welcomes more than two million people a year to its dazzling shores.