An architectural oddity hides in plain sight on this iconic London bridge.

These mysterious Viking chess pieces spent centuries hidden on a remote Scottish island.

This medieval church tower has maintained its clockworks since the 16th century.

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

A labyrinth hides in plain sight at each of the city's 270 Tube stations.

Tucked away in the Tower of London is the weapon once used to execute high-profile prisoners.

The library houses an incredible collection of some of the world's most impressive books and manuscripts.

These ornate arches show how the course of the River Thames has changed.

This studio was home to David Bowie's first single, even if it did turn away the Beatles.

The Tudor-style cottage in the middle of the square is not quite what it seems.

A unique tribute to the millions of animals who served and died for the British military.

The "lost friend” is the most famous of the six moai statues that were removed from Easter Island.

Never actually a tree at all, this spot was the site of London's public hangings for nearly 600 years.

These official units of measurement—including chains and perches—lie hidden beneath tourists' feet in a popular London hub.

A statue of the legendary Celtic warrior queen who fought the Roman invaders stands in one of the cities she once destroyed.

The fierce beast perches atop a pedestal marking where the historic City of London gates once stood.

A community of artists and entrepreneurs seeks a simpler life on London's waterways.

Six ravens are kept captive (but well-fed) at the Tower of London to prevent the fall of the Crown.

A charming 17th-century alley is lined with secondhand bookstores and antiquarian shops.

London's smallest police station is barely the size of a phone booth.

This South London cemetery holds the remains of more than 15,000 people.

A little sculpture with a large wardrobe.

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

Christ's blood allegedly preserved in a Belgian town.