Mexico – Yucatán Cenotes (Mérida)
Inland Yucatán state offers a different kind of cenote diving from the Caribbean coast. South and south-east of Mérida, along the Ring of Cenotes that traces the buried rim of the Chicxulub impact crater, the sinkholes are deeper and more vertical: many are entered by ladder or rappel, and the dives drop into wide bell-shaped chambers with tree roots, light shafts and stalactites rather than long horizontal caverns. Most sites are run by small communities (ejidos or haciendas) that charge an entrance fee and often require a local guide; dive trips are organised from Mérida. Cenotes inside archaeological zones, such as the Sacred Cenote of Chichén Itzá, can be dived only with an INAH research permit.