This was the second largest mercury mine in the world and one of the oldest preserved mine complexes in Europe.

According to a local legend, this old castle could only be built after a woman was immured in the walls.

This open-air, narrow-gauge railway museum pays homage to the region's transportation history.

The largest Roman amphitheater in the Balkans once held over 20,000 people, but managed to lay hidden for hundreds of years.

This living labyrinth made entirely of thorns is filled with art.

In the middle of a busy residential neighborhood, a small roofless church being reclaimed by nature.

A unique Soviet mosaic preserved on the facade of a shoe factory in Lviv.

The smaller of the three towers of San Marino is a former prison inaccessible from the ground level.

Walrus skulls and narwhal bones were found here while excavating a 900-year old church.

On an island south of Iceland, a large volcanic rock formation resembles an elephant.

This Khmer-era temple includes a lintel that was stolen and displayed at the Art Institute of Chicago for years before returning to Thailand.

The widest natural waterfall in Estonia is a sight to see in all seasons.

An ice field known for harboring an infamous Martian meteorite turned out to contain the oldest air on Earth.

A temporary art piece to celebrate LGBTQ Pride is now a permanent part of Stockholm's traffic landscape.

The extravagance of Portugal’s "Pink Palace" resulted in a noble title being awarded to its owner.

Crossing a suspension bridge above a forest is the only way to reach this 12th-century monastery.

A secluded, little-known temple hidden amid the dense jungle.

An impressive ensemble of sculptures that survived the Soviet regime.

Once a beautiful palace, this structure is now known as the ''museum of destruction."

This unique sculpture proved invaluable when it saved a train from careening off the tracks.

A permanent exhibition honors Queen, which recorded seven albums at the casino-based studio, including “Under Pressure” with David Bowie.

The Grand Mall in Varna hosts one of the biggest collections of Soviet-era paraphernalia in Bulgaria.

This abandoned gold mine found a second life as a post-apocalyptic film set.

A Hollywood-sign replica with a typo on a remote hillside.