Top Secret Swimming Holes

Travel Channel keeps things cool with a summer series dedicated to the world's most secluded, sexy and extreme natural places to swim. Six hourlong episodes take viewers around the globe to track down -- via hiking, climbing, boating and even dog-sledding -- amazing places to take a dip, jump off a cliff or explore underwater caves. The adventures include visits to a crystal blue 100-foot waterfall buried deep in an Arizona Indian reservation; the ancient Mayan underwater caves of Mexico; America's oldest commercial quarry in Vermont; and the only place on Earth where people can swim with manatees.