A planned settlement in Pennsylvania once housed the aristocratic refugees of the French Revolution.

This lush forest valley was once mined for lumber to the extent that it was once nicknamed "The Pennsylvania Desert."

These mysterious ancient stone spheres were created by a civilization lost to time and are now mostly lawn ornaments.

One of the Seven Wonders of the Modern World holds the world's tallest metal staircase.

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

A sacred well steeped in Pagan roots on the West Coast of Ireland.

This single room has survived the centuries with almost no deterioration.

One of Ireland's most infamous prisons for rebels including men, women and children.

Century-old shop, specializing in Occult products.

Ant sculptures march up the side of what used to be an iconic spot in punk rock lore.

Instruments, apparatus, and rare books all relating to chemistry and its related sciences.

An Irish Memorial commemorating those who perished due to potato blight.

The first American department store, and home to the largest operating musical instrument in the world.

Tour the dark and beloved poet's former cobwebbed basement, which may have inspired "The Black Cat."

The body of St. John Neumann and his collection of hundreds of relics, on display in a Philly church.

America's most famous museum of medical oddities is home to the remains of Albert Einstein's brain.

A layered tribute to the work of mosaicist Isaiah Zagar.

The land is home to swimming ponies and a legendary 18th-century treasure.

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

Memorializing an American tragedy of massive proportions.

An abandoned stretch of highway, deteriorating next to the operational one.

Steepest flood safety railway in the entire world.

Penn State's giant bug collection.

A dramatic, 360-degree recreation of Pickett's Charge in the Civil War.