The Sian Ka’an biosphere is more that 1 million acres (404,686 hectares) in size and is one of the largest protected areas in Mexico. Also somewhat remote and lacking major hiking trails, it’s best visited with a guide. Discover the reserve by boat, visiting Boca Paila Lagoon and Ascension Bay with a guide, snorkeling and searching for marine life along the way. Plus, a Caribbean lunch at Punta Allen—located at the very end of the Boca Paila Peninsula—is included.