This collection of 20th-century toys is filled with a lifelong personal toy collection brought from the U.S. to Amsterdam.

A marble Lucifer hides behind the pulpit of this Gothic cathedral.

This subterranean studio is filled with fascinating kinetic art.

This beautifully designed star-shaped fort was the premier defense system of the late 1500s.

A late-medieval Dutch castle with trick fountains in its whimsical water gardens.

Underground attraction offering tours of the foundational ruins of a church nave that collapsed in 1674.

For years, the remains of this ancient Roman fortress were hidden under an orchard.

The giant scales in this museum can still tell if someone is one of the devil's brides just by weight.

Elegant marble and old vaults fill this historic Dutch bank turned office space.

Rumored to have been frequented by Vincent van Gogh, it's the only remaining genever producer in the Hague.

Strange secondhand shop showcasing taxidermy and oddies

Hidden within a Netherlands crater is a stone bed that lets those who lie in it see the sky as a curved surface.

One of the oldest masonic temples in the Netherlands, built in 1757.

The world's largest collection of ships in bottles.

Remarkably preserved body discovered in a peat bog.

The U.K.'s first underground railway line is now a lively thoroughfare for runners and cyclists.

This extinct volcano rises above Edinburgh and is special for its panoramic views over the city.

One of the oldest scientific gardens in Britain, containing more than 13,302 plant species in its core collection.

The ruins of a medieval castle that once belonged to one of the most powerful families in the Netherlands.

A Parisian cemetery where the elite and artistic are interred beneath an eccentric collection of tombs.

The historic Masonic Lodge in which the first-ever female Mason was initiated.

A museum-like shop that has been producing clogs, brushes, and ropes for nearly 200 years.

A Portuguese Jewish cemetery filled with stunning grave monuments that date back to 1614.

Famed for its pie, this eatery has a hidden tunnel that allowed Catholics to secretly walk to church during the Reformation.