Actun Tunichil Muknal “Cave of the Stone Sepulchre” was first discovered in 1989. Located in the Tapir Mountain Reserve of the Cayo District near the village of Roaring Creek, this popular cave is rated as the #1 cave in Central America by National Geographic and listed as one of the top things to do in Belize. The ATM Cave is known to have been used by the Mayas for ceremonial purposes during the Classic Period. Most of the ceremonies and/or rituals were carried out at the entrance of the cave. The interior of the cave was considered to be more sacred for its proximity to the Mayan rain God, Chaak. Towards the end of the Classic Period, it is believed that the rituals moved deeper into the cave as a result of drought, thus believed to contribute to the collapse of the Mayan Civilization. The natural geological wonder of crystalline stalactites and stalagmites formations are not the only remarkable thing about the ATM. This 5-kilometer-long museum is filled with ancient Mayan artefacts and holds over 14 human skeletal remains of men, women and children.