South Carolina's last remaining slavery auction house is now a museum devoted to its own tragic history.

A tribute to Ponce de Leon's supposed quest for eternal youth.

This island hill is strewn with boulders carved by shipwreck victims from the age of sail.

Rumored to be the famed pirate's lookout tower, this historic stone structure is now just watching for tourists.

This Delaware River bridge is emblazoned with a catty slogan from a more prosperous time.

Infamous marsh filled with toxic waste, World War II-era London rubble, and dead mobsters galore.

On the Hudson resides one of the largest clocks in the world.

The only thing better than tubing down New Jersey's scenic Delaware River is doing so while eating a hot dog from a giant floating stand.

One of the world's largest model railroads is a mind-boggling achievement.

Beautiful views of the surrounding hills and birds of prey can be found at this sanctuary.

This strange, big-tailed beast became a Pennsylvania town's unofficial mascot.

A tour de force of a fountain, memorializing a man who loved fountains more than anything else.

This huge, disused viaduct is now a crumbling concrete underworld of covered in years of graffiti.

This jail which was in service for over a century is now open for curious visitors.

A local prank turned town icon.

The remains of a community that was forced to move for a dam that never materialized still rot in this Pennsylvania park.

This large garden vase urn has nothing to do with the seventh U.S. President—it was designed by one landscape designer to honor another landscape designer's contributions to the National Mall.

It was once the base for a series of domestic terror attacks.

This bridge over D.C.'s Rock Creek Park is sometimes called the "Buffalo Bridge" because of its four buffalo sculptures, which were cast from a single piece of bronze.

The only Leonardo Da Vinci painting in the Western Hemisphere.

A spectacular tribute to statesman and philanthropist Andrew Mellon.

A street in front of NASA's D.C. headquarters has been named in honor of the Black women who were essential to early spaceflight.

Surrounded by a verdant garden and a backdrop of ivy, a monument to beloved poet Khalil Gibran stands outside of the Lebanese embassy.

An echo chamber with a waterfall wrapped around its base at the Embassy of Canada in Washington, D.C.