The skeletal frame of a decommissioned gas-pumping station offers breathtaking views of greater Berlin.

One of the world's heaviest musical instruments towers within a popular urban park.

A replica of the Liberty Bell rang daily from West Berlin's City Hall throughout the Cold War.

Someone loved this song enough to carve all of its lyrics onto a tree trunk in a Berlin park.

A historic fire call point.

A monument to the three wars that led to German unification towers within a Berlin traffic circle.

A collection of abandoned typographic signs from Berlin and beyond.

Known simply as "The Hand," this famous public sculpture in Berlin was featured in a Depeche Mode music video.

An imperial church bombed to ruins during WWII now stands as a jagged memorial.

This platform is now a memorial dedicated to those who were deported during the Holocaust.

The rustic think-space of famed naturalist John Burroughs stands exactly as he left it.

10,000 flowered plants bloom in the City of Roses.

Climb to the top of its spiral spire for spectacular views of Copenhagen.

Climb this overlooked gem's spiral staircase and you'll be rewarded with spectacular views of Glasgow.

The old observatory in Copenhagen has a spiral corridor used as a racetrack.

This palatial spiral staircase was so unusual the name "snail" was given to the noble family who built it.

Portugal's National Pantheon has a history of curses, collapses and financial problems.

Ring the bell to enter a bar that looks equal parts museum and old curiosity shop.

This charming candle shop has been in business since 1789.

An early Portuguese serial killer's head is alarmingly well preserved in a jar at the University of Lisbon.

Elaborately carved to showcase the glorious wealth that the age of exploration brought to the Portuguese empire.

An ancient and majestic fortress that played an integral role in Portugal's road to independence.

This Industrial Age architectural and engineering gem helps visitors and residents alike traverse Lisbon, “The City of Seven Hills.”

A king's pet, a pope's gift, an artist's inspiration, and a tragic shipwreck.