This pre-Revolutionary War grist mill ground corn and flour for soldiers in seven American wars.

At Washington's Dulles Airport is a satellite museum (no pun intended) with three quarters of a million square feet of aircraft history.

This train station inspired the name of a 1970's rock band and provided the backdrop for their album cover.

This fairy tale forest hides scenes from some of the more obscure and bizarre Western nursery stories.

While most bridges allow roads to pass over water, this one allows water to pass over a road.

Christ's blood allegedly preserved in a Belgian town.

Amsterdam's former hotspot for public executions and dissections.

Established in 1638 to battle the Black Death, this botanical garden is a treasure trove of rare flora.

Cat art as far as the eye can see.

The old observatory in Copenhagen has a spiral corridor used as a racetrack.

Copenhagen's celebrated theme park and gardens.

The palace for King Gustav III was never completed, but the foundation remains tucked away in this city park.

The 19th-century home of Count and Countess von Hallwyl is now a museum.

A temporary art piece to celebrate LGBTQ Pride is now a permanent part of Stockholm's traffic landscape.

Several cannonballs of mysterious origins decorate two buildings in Stortoget's main square.

It is said that each of the white stones in the red facade of this medieval house represents the head of a murdered Swedish noble.

Sweden's "good old days" painstakingly re-created in a model village.

Stockholm's deepest subway station is also a stunning ecological wonder.

It houses the remains of a 17th-century version of the Titanic.

A rare surviving Victorian greenhouse designed specifically to house giant water lilies.

Stockholm's decidedly unique public transit system has doubled as the world's longest art gallery for decades.

Randy Senna's Fascination and retro arcade is home to the last Fascination game in New Jersey, and one of seven remaining as of 2021.

Spectacular mineral formations fill these caves, which have been used for everything from smoking meat to stashing illicit liquor.

The world's largest fully steerable radio telescope.