The design of this historic domed church was influenced by Thomas Jefferson and intended as a statement of religious freedom.

The longest escalator in the Western Hemisphere takes over three minutes to ride down.

An abandoned theme park with a strange and tumultuous past.

Moonbows over Kentucky.

The world's longest known cave system.

The body of one of the world's most famous outlaws is covered in cement and iron to prevent it from being stolen.

Home to the deepest rift anywhere on Earth.

A building so large that it has its own weather.

This abandoned NASA launch site is now a memorial to a trio of astronauts who were killed there.

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

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

Location of a reliquary containing bone fragments of 18 saints.

An 18th-century Spanish watchtower made entirely of seashell and concrete.

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

Former villa and estate of James Deering developed to preserve native tropical forests.

This historical swimming pool near Miami is emptied and refilled each day with naturally filtered water.

The highway's southernmost spot is a beloved local attraction.

A monument celebrating the idea of reaching inaccessible places.

The island residents are known for taking their quirky sense of humor with them to the grave.

The former home of the Nobel Prize-winning American writer is now home to dozens of six-toed cats.

A former waterfront market is now in the center of town due to some interesting Boston engineering.

This monument on Breed's Hill proves that one of the most famous battles of the Revolutionary War is misnamed.

The site of Paul Revere's historic two lantern warning.

Berthed at the Charlestown Navy Yard in Boston, "Old Ironsides" is the oldest commissioned warship still afloat.