The ATM cave is a rare opportunity to take a tour through almost perfectly preserved history and learn the story of an ancient civilization frozen in time. Dubbed by National Geographic as the world’s most sacred cave, the ATM cave is home to the Crystal Maiden, the skeleton of a sacrifice victim which has been completely calcified from remaining in the same spot for 1,000 years. This cave is believed to be highly spiritual and revered by the Maya as a gateway to the home of the Maya gods. The ATM tour is classified as extreme – it requires swimming, hiking, and climbing. Visitors will have to hike for about 45 minutes through the Tapir Mountain Nature Reserve and then are required to swim through the mouth of the cave to enter. Phones, cameras, and electronic devices are banned.