World War II bunker still standing on the New Jersey beach.

Steadily reminding Czechia of its past.

Unrepaired walls from a 1920 anarchist bomb attack.

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

Only hotel where you can legally launder money.

The site where Poe "in great distress, and ... in need of immediate assistance" likely died.

A 60-room castle constructed by a horse-racing heir.

Ruins of a once-prized railroad station in New York.

Radioactivity still cause for concern at this urban explorer's paradise.

Where a staggering 747 ships were constructed during World War II.

Waterway populated with abandoned projects, including a submarine.

A decommissioned military complex that's now a modern industrial park.

One-time winter retreats of prolific inventor Thomas Edison and his friend Henry Ford.

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

Astonishing collection of helmets, scientific instruments, and medical models.

Little Red Lighthouse under the George Washington Bridge.

The only theatre in the world constructed specifically for sound movement.

The world's brightest bioluminescent bay.

World's first "penitentiary," meant to be humane, drove men insane.

In all of the 29 years it was in operation, no prisoners ever escaped successfully... or so they claim.

Art deco landmark on the outskirts of Washington, D.C.

Largest Roman Catholic church in North America.

Oldest surviving example of a Dutch saltbox frame house in America.

Once home to seven different roller coasters, Glen Echo has undergone many transformations since its founding in 1891.