The Calcehtok Caves may be the most adventure-oriented of the grutas (caves) along the Puuc Route. Up to four kilometers (2.5 miles) of the cave can be visited, during which you squeeze through narrow gaps, teeter along slippery pathways, and crawl and clamber through muddy passageways.

Along the way are huge chambers filled with stalactites and stalagmites, and tiny rooms where archaeologists have found human bones and other remains of pre-Hispanic Maya ceremonies. Calcehtok’s caves are definitely less commercialized than others—you don’t need any technical experience, but be prepared to get dirty.

To get here, follow the signs on Highway 184 until you reach a turnoff that leads to a small parking lot. A guide should be waiting up the short path. (If not, it means he is with other people and you can either wait or come back later. Never enter this or any cave without a guide.)

There are several tours available, depending how far and deep into the cave you want to go. Prices vary accordingly, but it works out to roughly US$14 an hour for up to three people, with tours ranging from two to five hours. Before going in, agree with the guide how long the tour will last and how far into the cave you will get. If you have a flashlight, bring it as a backup. Do not wear flip-flops—tennis shoes or boots are best, although Tevas should be fine.