Bacalar

Founded in AD 435, Bacalar (pronounced baa-ka-lar) is one of Quintana Roo's oldest settlements. The town’s most notable feature is a cenote-fed lake of the same name—Laguna de Bacalar. The mix of freshwater and salt water that intensifies its color has earned this long, narrow body of water the nickname "Lago de los Siete Colores" (Lake of the Seven Colors). Marking the entrance to Bacalar is Cenote Azul, a crystalline cenote that's 300 feet deep and 600 feet across. The water is clean and the diving is excellent here.