When you visit Cancun or the Riviera Maya (Playa del Carmen) on Mexico's Caribbean Yucatancoast..I strongly recommend going on excursions. During my 4 days sponsored by Sol Mewlia & Paradisus Resorts, May 2012..we were taken for an exciting day here..Xel-Ha Park. No pollution, crystal clear lagoons. I rode an inner tube thru mangrove swamps..then donned my snorkel gear..and was astonished at the clear lagoons and sealife. The zipline was fun..and lunch was 'authentic' Mexican. 1great-trip.com