The Xel-Ha Inlet differs from most in not being a mere entrance leading inland from the sea, but also a confluence of underground waterways flowing seawards. The white sands and bright waters of the Riviera Maya, of which Xel-Ha is a formidable example, are due to the disintegrated particles of coral reefs over millions of years.

Xel-Ha Inlet houses over 70 recorded species of freshwater and seawater fish, including yellowtails, parrotfish, surgeonfish, jackfish, sergeant majors, grunts, snappers, bonefish, stingrays, chubs, doctorfish, and an occasional barracuda. The endangered queen conch inhabits the waters under careful monitoring and protection. Temporary visitors to the inlet include sea turtles and manatees.