Over two centuries old and counting, Madrid's massive botanical garden contains one of Europe's only desert environments.

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

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.

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.

Mountain where Jesus was first tempted by the Devil.

An unusual stroll through gentlemen's erotica demonstrates that pornography is timeless.

Madrid's romantically ornate crystal palace has been offering shelter to plants and art for over a century.

Step inside the first house designed by Catalan architect Antoni Gaudí, considered to be one of the first Art Nouveau buildings.

Gaze upon chocolate sculptures depicting everything from chariot races to Gaudí's famous church at this shrine to sweets.

This cemetery features modernist statues as strange as its name.

These secluded and abandoned anti-aircraft defenses have become one the most scenic viewpoints in Barcelona.

This semi-secret storybook hedge maze is also the oldest garden in the city.

One of Antoni Gaudí's most classic buildings is well-known for its "dragon-back" design.

A stunning architectural yet functional feat, towering over Oslo.

A collection documenting Nazi occupation of Norway, including a painting believed to be made by Hitler.

Norway's oldest cathedral still in use.

World's strongest whirlpool.

Longest road tunnel in the world features an air treatment plant and the illusion of daylight.

A Viking-style brewpub named for a Norse sea giant, in the heart of fjord country.

A thin pane of glass keeps visitors from sliding off this futuristic skywalk.

This "preacher's pulpit" once used for pagan ritual, is home to a new, and dangerous ritual.

Walk 2,300 feet above the ground on the "Troll's Tongue."

Some of the greatest minds in the history of Hungarian art and science converged in this café.