Mayans once saw caves as sacred underground passages to the underworld. Upon entering one of Guatemala’s large cave systems, it’s easy to understand this belief—they are dark, enormous, and even a little eerie. Rivers carved out many of Guatemala’s most prominent limestone caves. In some places, you can ride inner tubes through the caves or go spelunking with a flashlight. The caves can be as tall as 200 feet (60 m) and as wide as 100 feet (30 m). They are utterly awe-inspiring.