The first green space constructed on an elevated viaduct.

3,000 market stands in five former Zeppelin hangars.

A black cat protests the City Guild in Riga's Old Town.

A lone cannonball remains lodged in the walls of the Hotel de Sens as a sober reminder of a revolution.

Museum preserving torture methods from the past.

Abandoned railway line circling the city of Paris.

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

France's most famous cemetery, with some of its most curious tombs.

Weird wax anatomical models reside here, as do other anatomical specimens.

This iconic Parisian bookstore doubles as the "Tumbleweed Hotel" for traveling writers.

Notorious artist squat renovated into legal studios.

The celebrated eyesore created by starry-eyed sweethearts.

The curious underground history of keeping Paris clean.

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