Hundreds of pieces of ancient Taíno art cover the walls of this Caribbean cave system.

This trio of Dominican cave lakes comprise a colorful biosphere of natural life.

Built in 1512, the oldest cathedral in the Americas.

The first hospital in the New World.

Renowned restaurant tucked in a cave once occupied by buccaneers.

Aqueducts have dramatically changed this old lake, now home to tufa towers and its very own species of tiny brine shrimp.

The neon signs from Las Vegas' past find their final resting place at this unusual graveyard.

A peculiar mansion built by the troubled heir to the Winchester Rifle Company fortune.

Eons old volcanic activity created one of the most stunning rock formations in the United States.

This Nevada lake holds its titular natural pyramid and, if the legends are true, a number of dangerous spirits.

This naturally heated mountainous creek has created a group of neon blue pools of potentially deadly boiling water.

Towering basalt columns, a creation of fire and ice.

A decommissioned Naval base now rents itself out for people who want to blow stuff up.