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

A preserved oak tree about 3,500 years old found in Riga, Latvia.

3,000 market stands in five former Zeppelin hangars.

A little sculpture with a large wardrobe.

Cozy basement bar sports an inventory of over 2,000 beers.

This collection of over 50 murals celebrates Brussels' rich history as the self-proclaimed home of the "comic strip."

Brussels' favorite peeing boy has a sister.

From Tintin to the Smurfs, Europe's greatest graphic icons are celebrated in a grand Art Noveau gallery.

Climb inside an iron crystal magnified 165 billion times its normal size.

The post-apocalyptic remnants of a bucolic town ruined by a plane crash.

This Parisian café sticks almost exclusively to an ethos of reuse.

Ghosts of France's colonial past.

This massive library holds what was once the largest book collection in the world.

The celebrated eyesore created by starry-eyed sweethearts.

The remains of the great moral philosopher reside in a university in London.

The only university zoological museum in London houses extinct animals, bizarre natural history specimens, and a Micrarium of microscopic creatures.

Famously misunderstood wonder of the ancient world

Want to properly offend a king? Sculpt a giant hill figure in chalk of him riding out of town.

Eighty million natural history specimens call this gargantuan museum home.

Spitalfields' regal market goat is said to be a monument to the area's migrant population but most are pretty sure it's just a goat.

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

The anatomical-pathological collection of a man who changed surgery.

The signs of a long buried road can still be found hidden beneath a London sewer grate.

"There's nothing there," and other lies the KGB told us.