Number One on National Geographic's list of Top Ten Sacred Caves in the world is the ATM in Belize!

From the National Geographic book Sacred Places of a Lifetime

Actun Tunichil Muknal, Belize

In myths, journeys to the underworld are never easy, and after visiting Actun Tunichil Muknal (Cave of the Stone Sepulchre), you may feel that you have been through your own epic test. Access to the Maya sacrificial site within the cave involves hiking, wading, and underwater swimming, but nearly a mile (1.6 kilometers) underground you will reach the resting place of the “crystal maiden,” a complete female skeleton that sparkles from eons of crystal calcification. The cave also contains Maya pottery shards, many showing the “kill hole” intended to allow spirits to escape.