Sian Ka'an Biosphere Reserve (Reserva de la Biosfera Sian Ka'an) encompasses the Boca Paila Peninsula and mainland Quintana Roo s. of Tulum and e. of Mex. 307. Designated as a protected area by the Mexican government in 1986, Sian Ka'an (the name means “place where the sky is born”) includes a variety of habitats: tropical jungle, drier areas of tree-speckled savanna, coastal mangrove flats and some 70 miles of offshore coral reefs.
Most of the reserve is off limits to tourists, but the beaches and jungles on the Boca Paila Peninsula can be explored by visitors. Take the Boca Paila/Punta Allen road off Mex. 307 (turn left if traveling southbound, right if traveling northbound; the intersection has a traffic signal and is signed “Playas/Punta Allen”). The road runs east for a few miles and then continues south through Tulum's hotel zone. About 15 kilometers (9 miles) from the Mex. 307 junction is the entrance to the reserve, marked by a guardhouse building (Caseta de Control). Day visitors must register at the guardhouse; from this point there is access to secluded beaches, and kayaks and bikes can be rented.
Tulum-based Sian Ka'an Community Tours offers guided excursions to the Muyil ruins as well as activities like a float down a canal while wearing a life jacket, boat tours and a trek through jungle to secluded, palm-lined beaches.