Actun Tunichil Muknal listed 2nd on Joshua Berman's list of 10 Unexpected Adventure Trips in Central America, which ran today in this month's issue of Men's Fitness. Belize actually has 3 spots on the list, Ragamuffin sailing trips and 5 coutry doomsday ride being the other 2.
"If you’ve never been in a cave, Aktun Tunichil Muknal is a must. In addition to swimming-wading-squeezing-crawling-hiking a half mile deep into the Maya underworld, you get to experience a unique experiment in the world of archaeology and tourism. In the ATM caves, officials have left 1000-year-old bones, pots, and other artifacts in situ, instead of hauling them off to labs and museums. The crystal maiden herself is a full-body skeleton, covered in calcite crystals which sparkle in your headlamp’s light."