The Mexican state Quintana Roo is located in the east of the Yucatan Peninsula. It has more than 1.5 million inhabitants. The capital is Chetumal, but the largest city is Cancun. The north of the state is washed by the waters of the Gulf of Mexico, the east coast touches the Caribbean Sea. The state coast is bordered by the second largest coral reef on earth - the Mesoamerican coral reef. Most of the Yucatan Peninsula is formed by a large limestone karst plate. The highest point is at an altitude of 241 meters. Limestone soils are porous and allow rainwater to be filtered into deeper soil layers. Under the surface, huge underground water reservoirs are created - aquifers. There are also cenotes - natural wells of large dimensions. There are many sites and buildings built by the Mayans on the territory of the state. Such are - Tulum, Cobá, Kohunlich, Dzibanché. Steve