This bridge was constructed from the rubble of the infamous Bastille.

This banal Parisian entranceway is not what it seems.

Exquisite wall sculptures carved in secret by an early quarryman in an obscure corner of the Paris Catacombs.

This Peruvian bone silo lined with hanging human skeletons and hundreds of skulls is topped with a remarkable Michelangelo replica.

Lucerne's central prison was converted into a tourist hotel with a bare minimum of changes.

This architecturally eclectic early-20th century mosque was built as a place of worship for the Islamic followers of a Jewish messiah.

This tiny Bulgarian town offers a stunning location in the mountains and a storied history.

A little-known park with unusual, half-ruined structures and a mystical energy.

An autonomous republic of Orthodox monks.

This ancient structure appears Roman, but was constructed during the 16th century and was utilized until 1911.

An unusual ode to the late Irish playwright, complete with a squiggly bust and coffin-shaped bench.

This coffee shop lies hidden beneath a historic church.

A mysterious shape catches the eye in this 16th-century painting.

One of the world’s leading and most extensive archives on the Holocaust, the Nazi era, and genocide, this collection includes published and unpublished works, press cuttings, photographs, and eyewitness testimony.

Home of one of history's most famous cartoonists just as he left it.

A relic from one of London's worst 19th-century slums.

Visitors can explore the role of mysticism throughout the ages inside this interactive museum of magic.

Berlin's old airport.

What started as a tongue-in-cheek shrine is now a full-blown museum celebrating "The Hoff" and his longtime love affair with Berlin.

On the Spree bank, discover one of the last reminders of a symbolic wall that divided, and was torn down by the people.

A Spanish-style estate that has traded black ties for rock concerts.

A bronze sculpture of Lenin’s likeness outside Havana surrounded by 12 human figures in solidarity with the Bolshevik Revolution.

A lovingly curated curio shop in which the taxidermy wear newspaper party hats, and peanut shells are spread across every surface.