The only Maya ruins facing the Caribbean Sea, perched on a 12-meter cliff above turquoise water. In Tulum, El Castillo watches over the coast where Maya trading canoes once arrived. You tour the site among iguanas basking in the sun and, when you're done, head down to the beach that stretches right below. History and the Caribbean in the same postcard: no wonder it's the icon of the Riviera Maya.