From within Mexico, Cancun is reachable by the Yucatans intricate and efficient bus system. The main regional terminal is downtown, on the corner of Av Tulum and Av Uxmal. There, you can connect with a local line. Any of the buses traveling south on Av Tulum labeled Zona Hotelera will take you to your hotel or resort. You may want to stop off first at the State Tourism Office (Av Tulum 26, south of the bus station and next to Banco Inverlat, phone 884-8073 or 881-9000, open daily from 9am to 5pm). The staff at the center is bilingual. Another worthwhile stop for insider information is the Conventions and Visitors Bureau on Av Nader at Av Coba, phone: 884- 6531, www.gocancun.com.