One of the deepest blue holes in the world.

This staircase in a lush tropical grotto was built by enslaved laborers and renamed to honor Queen Victoria's role in ending slavery in the British Empire.

Bronze footprints mark the path where a civil rights leader tried to march in peaceful protest before being knocked unconscious.

The walls of America's oldest masonry fort famously "swallowed" cannonballs.

In this case, 'zero' marks the spot where the iconic Old Spanish Trail ends.

A luxurious 1880s hotel with its fair share of Tiffany stained glass, Edison electricity, and of course, ghosts.

The ruins of an open-air theater built on this Georgia island in the 1970s.

This bar hosts an ever-evolving napkin art installation devoted to an American president.

You’ve heard of bookworms, but this small sculpture at a university library may be the world’s first bookbee.

A mailbox that saved a nature reserve.