Aktun Chen   Aktun Chen is a natural park located 66 miles away from Cancun, in the heart of Riviera Maya consisting of a spectacular 5,000,000 year-old cave with a magnificent vault, discreet illumination and easy walk paths making the visitors comfortable.   The caves contain thousands of stalactites, stalagmites and rock formations, sculpted by the water along with a 12m depth sinkhole with clear blue water and abundant wildlife. It name means “cave with an underground river inside”. There are no set schedules for tour and there are guides available to take you when you arrive.