Three connected pink triangles memorialize persecuted gays and lesbians throughout history.

This interactive sculpture allows visitors to leave a message in case a friend passes by.

Rare wooden escalators lead deep down into an otherwise staggeringly monotonous tiled tunnel.

This small corner bar is home to a rare 1930s dance organ that still plays tunes for one Euro.

This statue dedicated to the story of a Flemish boy and his dog was relatively obscure in Belgium, but a cult sensation in Japan.

A man throwing a giant severed hand towers over Antwerp’s main square.

A Parisian cemetery where the elite and artistic are interred beneath an eccentric collection of tombs.

A popular shrine where the Blessed Virgin allegedly appeared in 1830, displaying a holy armchair and two incorruptible remains of Lady Saints.

The remains of the medieval wall that once surrounded Paris with ties to the construction of the Louvre.

Remains of Roman amphitheater hidden in a sleepy quarter of Paris.

The world's largest reflecting pool is just two centimeters deep.

An unusual but excellent display created in the 1930s as propaganda against the Freemasons.

The Cathedral of Salamanca has a number of unusual carvings but none so surprising as a modern astronaut.

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.

The facade of this 16th-century building is decorated with carvings of 300 seashells.

A hidden medieval crypt where a famous legend says the devil used to teach black magic.

Not far from the busy city lie these remains of a time when the world was on fire.

Not far from where one of the most famous Swedes of all time is buried, an infamous man was put to rest.

A Stockholm metro station is home to an escalator that is not only the longest in Sweden, but among the longest in the world.

This building, previously used as a courthouse, has an unusual geological feature in its basement.

There are hidden patterns on the subway seats of some Stockholm metro cars.

This poured-concrete water reservoir is a gem of modernist architecture well-hidden in a city forest.

Hamburgers are intensely proud of their tunnel beneath the river.