
© R FriedlandAt Xplor, there's an entire world of underground adventures including swimming and rafting in underground rivers. Above the earth's crust, there's a network of zip lines that looks like freeways in the sky, and a three-mile track where you can drive an amphibious buggy through the jungle, into caves and on suspension bridges over water.

Rio SecretoTouring Rio Secreto's was a highlight during a trip to the Riviera Maya. You don a helmet with a lamp and a guide takes you on a combination walk and swim to experience the wonders of Mexico's longest underground cave system in a natural, untouched state.

© Dick FriedlandFloating downstream in Sian Ka'an, a Biosphere Reserve in Mexico and a UNESCO World Heritage Site, I thought about the Mayans who created these waterways centuries ago. I was swimming behind a boat toward the end of a day that included kayaking among mangroves to watch birds, motoring past a dozing crocodile and photographing more than a dozen different species of birds.

© R FriedlandIf you want to scuba dive or snorkel in a cenote while you are in Cancun or the Riviera Maya, read about our experience diving in Dos Ochos, an underground cave system in the Yucatan Peninsula, Mexico.

© L FriedlandWhile riding a SkyCycle through the treetops at Hidden Worlds you can stop to enjoy the scenery and listen to the birds sing. The family-oriented Hidden Worlds adventure park is tucked into the jungle, with places where you can ride a zipline or rappel into a cenote. The staff is bilingual at this non-profit park (proceeds go to benefit various Third World causes) and many of the people working at the park are members of the local Mayan community.

© R FriedlandIf you want to escape from crowded beaches, go horseback riding along a beach and in the surf, take an ATV ride through the jungle, or go kayaking and snorkeling off a private, pristine beach, plan at day at Punta Venado.