Ring of cenotes, Natural sinkholes formation in Yucatán, Mexico

The Ring of Cenotes is a semicircular alignment of cenotes in Yucatán, Mexico, with a radius of about 90 km (180 km in diameter), centred slightly north of Chicxulub Puerto. Its perimeter lies on continental land, where the limestone of the peninsula platform is fractured into a network of caves that act as underground rivers and water reserves. The 99 cenotes within its Ramsar designation each cover about 9 hectares, for a total of 891 hectares.

The sinkholes trace their origin to the asteroid impact about 66 million years ago that left the Chicxulub crater, creating a circular fault line where limestone slowly gave way over time. Maya communities then built settlements along this arc because the water sources it provided were among the most reliable in the region.

The name cenote derives from the Maya word dz'onot, later adopted into Spanish. The ring's cenotes are not only tourist sites: they are the region's main freshwater source, and the Ramsar designation singles out 99 of them, each about 9 hectares, for priority attention. The cenote at the approximate centre of the arc is Santo Toribio, in Cuzamá municipality.

The sinkholes are spread across a wide area, so planning a route from Mérida or a nearby town is a practical starting point, and having access to a vehicle makes visiting several spots in one day much easier. Paths leading down to the water can be uneven or slippery, so solid footwear is a good idea.

The ring is not the crater rim: it is a semicircular fracture zone about 180 km across, centred slightly north of Chicxulub Puerto, where the impact fractured the limestone. Within its Ramsar declaration 99 cenotes are listed, each about 9 hectares, for 891 hectares in total; the central one is Cenote Santo Toribio in Cuzamá.