Along the Caribbean coastline located on the eastern portion of the Yucatan Peninsula, Quintana Roo is the Mexican state where you will find the energetic Cancun (to include Puerto Nizuc), the Riviera Maya, Playa del Carmen and Tulum. The second largest barrier reef in the world begins near Cancun and continues along the whole length of the Riviera Maya continuing southward to Guatemala. Most popular activities include snorkeling, scuba diving, swimming in natural sinkholes called cenotes, zip-lining, horseback riding, sailing, and guided jungle tours. Archeology is also a big tourist draw in the area, including the popular archeological sites operated by the Instituto Nacional de Archeological such as Tulum on the coast, and Chichen Itza and Coba located some distance inland.