One of the largest dry-cave systems on the Yucatán Peninsula, Loltún ('stone flower' in Maya) provided a treasure trove of data for archaeologists studying the Maya. Carbon dating of artifacts found here reveals that the caves were used by humans 2200 years ago. Chest-high murals of hands, faces, animals and geometric motifs were apparent as recently as 25 years ago, but so many people have touched them that scarcely a trace remains, though some handprints have been restored.
A few pots are displayed in a niche, and an impressive bas-relief, El Guerrero, guards the entrance. Other than that, you’ll mostly see illuminated limestone formations.
To explore the labyrinth, you must take a scheduled guided tour, usually in Spanish but sometimes in English if the group warrants it. Please tip your guide, as this is the lion's share of their touring income. Tours last about one hour and 20 minutes, with lots of lengthy stops. Some guides’ presentations are long on legends (and jokes about disappearing mothers-in-law) and short on geological and historical information. The sign says the route is 2km, but in reality it's around 1.1km. Colored lights illuminate the route.
Colectivos (shared vans) to Oxkutzcab (osh-kootz-kahb; M$60, 1½ hours, frequent) depart from Calle 67A in Mérida, beside Parque San Juan. Loltún is 7km southwest of Oxkutzcab, where you can catch colectivos (M$20) to the caves from Calle 51 (in front of the market). A taxi costs about M$120.
Renting a car is the best option for reaching the Grutas, though; once you’re out of Mérida it’s easy going on pretty good roads.