A Swiss amusement park entirely dedicated to the theory of ancient astronauts.

Featuring a meatless buffet fit for kings, this family-owned Zurich eatery is considered the oldest vegetarian restaurant in the West.

Historic fortifications form the boundary of Vatican City, but it’s not entirely surrounded by walls.

This cubist Vienna church building looks like some sort of alien stonehenge.

This Czech church doubles as something of a permanent fashion exhibition for a statue of the Infant Jesus.

Despite attempts by local police to discourage it, Beatles-inspired graffiti has been a means for artists to air grievances for decades.

Synagogue built from the stones of Solomon's temple contains the golem of Prague.

This spooky statue sits outside a famous Prague theater.

The fairy tale castle of the "fairy-tale king."

The prototype for all Nazi concentration camps.

Horrifically creative torture devices and shame punishments line the walls of this chilling museum.

This Nazi-built amphitheater was constructed on a sacred mountain site used by various German cults.

This historic funicular system combines the old with the new while offering delightful views over the surrounding valley.

Sitting in the basement of a castle, the largest wine barrel in the world is bigger than most apartments.

The attic of a four-century-old canal house hides a clandestine church.

Amsterdam's narrowest house facade is a monument to 17th-century tax evasion.

Unsurprisingly, Holland is home to one of the most magnificent flower gardens in the world.

Peek through a transparent pyramid and drink in the mountain made of books.

A miniature city, once ruled by the Queen of the Netherlands.

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

This still-celebrated home was a radical architectural experiment in 3D De Stijl.

The world's largest bicycle shelter can hold more than 12,500 two-wheelers.

'The Letters of Utrecht' lays out a ribbon of poetry one letter at a time, with no final verse in sight.

This historical Netherlands fortress still bears the marks of its single siege.