Howler monkeys boomed from a ceiba tree as I hooked into a harness, preparing to be lowered into a cave half-submerged by an underground river, where the remains of ancient Maya lay hidden beneath crystal-blue water. It was the apex of an archaeological adventure I undertook while on the Yucatán’s Riviera Maya. Chablé Maroma and Etéreo, Auberge Resorts Collection each arranged unique experiences with excellent guides (a Mexico expert in the Andrew Harper Travel Office liaised with the hotels on my behalf). Both work with Dante García, the man who took us snorkeling amid the bones.