Under the jungle of the Riviera Maya lies the longest surveyed underwater cave system on Earth, hundreds of kilometres of flooded limestone passages linking the cenotes, the sinkholes that were the ancient Maya’s only fresh water and their gates to the underworld. Cenotes like Dos Ojos are open for swimming and snorkeling in unbelievably clear water; the deep cave system beyond is first-rate (and lethal) technical cave diving only. It holds Ice Age human and animal bones among the oldest in the Americas. PUBLIC cenote swimming; the caves are experts-only.
Mexico
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