A 1,215-foot tunnel transports pedestrians beneath the River Thames.

A student driver's nightmare.

One part local history, 99 parts gruesome haunted house.

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

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

The largest fountain in Bratislava.

Thousands of slain Soviet soldiers are buried within the shadow of this enormous obelisk.

This Slovak bridge is known both for its connection to a national uprising and its UFO-shaped eatery.

This Slovakian statue of an emerging sewer worker might just be a bronze peeping tom.

Construction of Barcelona’s iconic (but controversial) church was finally completed in 2026—a century after the death of its architect.

This mysterious but iconic tapered tower appears in many Azeri fairytales and legends.

Once a black market electronics marketplace, now an otaku shopper's paradise.

Not quite the menace it once was, this monster still has some chops.

A jaw-dropping "megalibrary" that turns book-browsing into a geometric adventure.

A 125-meter long "tribute to the Brazilian people."

Model Trains and Much More in Hamburg.

Eighty million natural history specimens call this gargantuan museum home.

This ornate Victorian marketplace was the setting for Diagon Alley and the Leaky Cauldron in the first ‘Harry Potter’ film.

The largest cave chamber in Britain—big enough to fit a whole cathedral inside.

Inside this station, the 1945 film "Brief Encounter" is played on a loop daily.

This noble mash-up in eastern Luxembourg is part Medieval, part Renaissance, all castle.

An expansive complex of subterranean tunnels is all that remains of one of Europe's most formidable medieval fortresses.