Cenotes are a feature of the Yucatan peninsula. They are the aftermath of erosion on coral limestone, and changing water levels. Some cenotes are just tiny crevices while others can be as large as one hundred meters across. Many cenotes are closed to the public or are on private properly. Some, like the Sagardo Cenote Azul are open to the public for a fee, and have facilities such as cabins and restaurants on site.