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

Abandoned for decades, trains still pass through the now-restored remains of one of Madrid's first metro stations.

Hundreds of stone stairs and a winding medieval bridge connect this haunting Spanish island to the mainland.

A stately palace has been converted into the world's largest cannabis museum.

A lush indoor jungle fills this bustling Madrid transportation hub.

An ancient Egyptian temple in the middle of Madrid, Spain.

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

Mountain where Jesus was first tempted by the Devil.

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

A beautiful but toxic fountain of mercury.

The ruins of a medieval castle that survived two sieges.

These hilariously laughing bronze figures lampoon empty promises while encouraging civic engagement.

A local train station entrance hall doubles as a sanctuary for barn swallows.

This bust remembers the haunting local legend of a murderous monk.

According to a local story, this tree's blossoms signal the end of war.

This "Atomic Egg" appears on the city of Garching's coat of arms.

This unusual sculpture depicts how coins were made when minting was done by hand.

A funerary monument for two brothers who served in the Roman cavalry.

Dating back to the Pre-Roman Iron Age, this piece of bread is Europe's oldest surviving formed bakery product.

One of the largest numismatic collections in Europe fell victim to a huge theft.

This gilded emblem was once stolen by a Cookie Monster impostor, who demanded a charitable ransom for its return.

This unusual small wind turbine in Germany has only a single rotor blade.

Blending modern art with Baroque architecture, this wondrous mosaic grotto serves as the late artist's final creation.

The “Coin Cabinet of Dresden” houses a collection of over 300,000 numismatic artifacts, one of the largest of its kind in Europe.