A lush indoor jungle fills this bustling Madrid transportation hub.

The 2,000-year-old Roman columns are hidden within Barcelona's Gothic Quarter.

The largest Art Nouveau complex in the world is a Barcelona hospital with a 600-year-long history.

A temple to modernity, tucked away amid Barcelona's more well known museums.

One of the most photographed buildings in a city known for its Modernista architecture is an abandoned squat.

Turntable anonymously received orphans, alms, and groceries.

Commonly acknowledged as the only public monument to the Devil himself.

This former Baroque palace on the historic Calle Montcada is a rare architectural gem and was once the meeting place of an aristocratic scholarly society.

Spanning the El Chorro gorge, this pathway used to be one of the most dangerous crossings in the world.

Week-long block party becomes a competition for the best decorated street.

Now a hotel, this former bank was the site of a robbery that spawned a psychological phenomenon.

This Stockholm light tower can be controlled by anyone with a smartphone.

The library's graceful rotunda is like a bibliophile's temple.

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

An illuminated manuscript comprising the life's work of a lone monk, inexplicably decorated with a portrait of Satan himself.

Theme park featuring miniature replicas of European monuments.

Meet the bronze beloved pet to a family of famous peeing statues.

Cozy basement bar sports an inventory of over 2,000 beers.

Oldest Museum of the Netherlands is a true cabinet of curiosities.

A former plague hospital turned medical museum.

The Bloemen Route, or “Flower Route”, stretches 25 miles through prime Dutch tulip country as a result of “tulip mania,” the world’s first economic bubble.

Colorful and chaotic stacked hotel in North Holland.

This collection of over 50 murals celebrates Brussels' rich history as the self-proclaimed home of the "comic strip."

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