The Yucatán's Caribbean coast is divided into two major areas. The stretch from Punta Tanchacté to Punta Allen is called the Riviera Maya; it has the most sites and places to lodge, and includes some of the Yucatán's most beautiful ruin sites. The more southern stretch, from Punta Allen to Chetumal, has been dubbed the Costa Maya. This is where civilization thins out and you can find the most alluring landscapes, including the pristine jungle wilderness of the Reserva de la Biosfera Sian Ka'an. The Río Bec Route starts west of Chetumal and continues into Campeche.