Mammoth Cave: Kentucky
This one is actually an entire cave system and not just a singular cave. Mammoth Cave National Park is home to over 400 miles of passageways, the world’s most well-known cave system.
It’s located within the Green River valley, and its winding chambers, pools, and limestone labyrinths are equally beautiful AND creepy. Ten different types of tours allow visitors to explore the illustrated, historical, and dripstone areas.
The cave complex is exceptionally well known for its natural entrance and Gothic Avenue, a passageway that’s filled with historic stone monuments and signatures from its 19th-century visitors. Tours for the area can be reserved in advance online.
