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

This once sprawling resort now sits abandoned, filled with graffiti and vibrant colors from an era long passed.

The Polish capital has had a deep connection to its guardian mermaid for almost a millennium now.

St. Mary's features one of the most spectacularly decorated cathedral interiors in all of Europe.

This Polish cave has housed a dragon, a brothel, and an enduring legend.

The former Nazi concentration camp stands as a museum to remember this dark chapter in European history.

An underground city of salt.

This hospital fell into ruins after failing to act as the advocate for the mentally ill it was designed to be.

Once considered a marvel of engineering, this 107-mile canal played an integral role in building New York City.

Take a step into the workshop where Edison and his employees revolutionized the world.

Memorial to the 137 lives lost on a ship fire, the whole hulk of which washed up on the Asbury Park shore.

This evocative New Jersey statue memoralizes the Polish victims of a Soviet massacre.

Rising out of a clearing in New Jersey's Pine Barrens is an Aztec-inspired monument to the "Lindbergh of Mexico."

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

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

An allegedly cursed tree represents a town's reckoning with a racist past.

Memorial built in 1922 in remembrance of WWI casualties.

A bronze plaque at an intersection in Hoboken marks the place where the game of baseball first took shape.

A simple plaque remembers an act of WWI terrorism that obliterated an island and forever scarred the Statue of Liberty.

How this Pine Barrens hill got its name is uncertain, but on a good day the view from the fire tower is crystal clear.

New Jersey's last historic covered bridge was rebuilt from pieces of the original 19th-century structure.

One of New Jersey's oldest surviving buildings still bears the mark of our former British overlords.

World Trade Center memorial likened to a woman's sexual organ.

These unassuming lighthouses have seen the first reading of the Pledge of Allegiance, the first wireless transmission, and more than one mystery.