Tulum was an ancient Mayan fortress city that rose to power toward the end of the Classic period. The most iconic of its structures, the Castillo, is perched on the edge of a cliff overlooking the clear turquoise blue waters of the Caribbean. The cliff-top Castillo, with its beachfront location and lush green landscape, is the image most often associated with the Mayan Riviera, you’ve probably seen the postcards. Exploring Tulum's surrounding areas also pays big rewards: there's the massive Reserva de la Biosfera Sian Ka’an, secluded fishing village Punta Allen and the ruins of Cobá.