One of the first commercially successful anthracite-powered iron-making operations in North America.

A New Jersey state park that was once Napoleon's brother's sprawling estate.

This semi-spooky remnant of an abandoned hotel provides fantastic views.

The longest-covered bridge in the state of Maryland.

Inside this 150-year-old barn turned antique shop is a vast array of items for curios hunters.

Designed by Horace Trumbauer in 1893, this Gothic-style castle is now a home for academics.

Old neon signs from the City of Brotherly Love provide a snapshot of the city’s evolution.

One of Philadelphia's largest murals resides hidden under this bridge.

The last of Philadelphia's wood-paved streets is now a landmark of terrible engineering.

Century-old shop, specializing in Occult products.

South Philadelphia is home to Keith Haring's only surviving in situ collaborative public mural.

The world's third-largest crystal sphere has sat in the Penn Museum since 1927 with the exception of one outlandish theft.

These medicine cabinet staples are part of the museum's collection of everyday objects.

The corporeal remains of Napoleon III's dentist rest under this 15-story obelisk.

A beloved horticultural oasis on the grounds of a wealthy family's former estate.

This collection of odd proofs of concept is like taking a walk through the imagination of a Victorian engineer.

The final resting place of the tragic king and queen of the Jazz Age is tucked away in a small Maryland graveyard.

This scenic Maryland park was the site of one of the worst prison camps of the Civil War.

Two dozen pinball games hidden away inside a most unlikely location.

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

Captain John Smith thought these cliffs were amazing in 1608 but sharks thought so 20 million years before him.

This abandoned sea fort has become an accidental bird sanctuary.

This simple convenience store sits on the location where the Ouija board was named—and has a plaque to prove it.

A cave on the Maryland border where civilians took refuge during the bloodiest battle of the Civil War.