A favorite Paris bar for U.S. expats, including Gershwin, Hemingway, and James Bond.

Paris' linguistic guide to the international language of, yes, love.

Notorious artist squat renovated into legal studios.

The vast, legendary catacombs hold secrets much stranger than stacked bones.

The macabre collection of Jacques Sirgent, an expert scholar on the undead and all of their trappings.

This series of Scottish caves has no clear purpose other than baffling historians.

One of the oldest scientific gardens in Britain, containing more than 13,302 plant species in its core collection.

17th century streets hidden under Edinburgh were once a breeding ground for the black death.

The fountain marks the area where hundreds of accused witches were burned at the stake.

These fantastically named natural pools look like something out of a Scottish myth.

An island made out of shells, including a cemetery.

This tiny, tranquil Senegalese island serves as a powerful symbol of the Atlantic slave trade.

Despite a fraught and controversial history this African island holds a powerful monument to the tragedy of the slave trade.

An artistic tribute to the famous singer, just around the corner from where he was born.

Thanks to modern navigational tools we now know that the true prime meridian runs through a park next door.

This massive collection of British military artifacts includes the heartbreaking personal letters of the men in the trenches of WWI.

A makeshift shrine to the late rock star is still kept up on the nondescript façade outside 1 Logan Place.

The perfectly preserved underground rooms where Churchill plotted the war against Germany.

An easily overlooked stretch of ornate window fronts and gaslight lamps that could be right from the pages of Dickens.

Banksy gives themself artistic license with this piece of London street art.

This churchyard arbor is surrounded by hundreds of gravestones placed there by author Thomas Hardy.

One of the few remaining casualties of the London Blitz, this destroyed church has become an enchanting public garden.

A kaleidoscopic warehouse-maze of handmade neon signs.

A leafy, peaceful oasis nestled in the heart of Glasgow's busy south side.