No need to strap in for a “ride” on this walkable roller coaster.

This former steel and coal plant is now a neon-lit industrial fantasia.

In the hometown of the Catholic saint and Nobel Peace Prize winner, a memorial dedicated to her legacy.

This fortress dates back to the 6th century and is also the site of a controversial abandoned restoration project.

Birthplace of the "Cat in the Cradle" and a cluster of iconic, original windmills that let the Dutch tame the seas.

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

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

Home to three historic ships from the age of Vikings.

One man's exploration of the human form, including the bizarre and delightful "Man Attacked by Babies."

The design of this beautifully crafted building was inspired by Norwegian glaciers.

The gorgeous library at Trinity College is home to remarkable treasures of Irish identity.

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

Spain's largest bullring offers a unique glimpse at architecture and history.

An amazing collection of wax anatomical models and terratological models.

The video game-themed street art first popped up in the French city.

The tradition of open-air secondhand and antiquarian bookselling in Paris dates back to the Renaissance.

Bacteria and algae give the salty water its bubblegum hue.

A series of abstract, silly sculptures represent the works of a great modern classical composer.

A luxury hotel housed in a former 15th century Gothic church.

This 1,300 year old monastery built atop a single rock was once only accessible depending on the whims of the tide.

Part modern art project, part traditional chapel, this see-through church is only substantial from the right angle.

The Devil’s own choice when he needs a drink in Brussels.

Site of a classic 19th-century physics experiment to prove the earth is rotating.

A fascinating and enormous collection of natural history exhibits stained by a dark colonial legacy.