This mosque was based on Sub-Saharan Islamic architecture and created for the Senegalese Tirailleurs.

One of the largest ochre quarries in the world, hidden in a limestone landscape.

This 18th-century sundial was designed to calculate the date of Easter each year.

A glamorous hotel that once accommodated French resistance fighters and concentration camp survivors.

This mural painted by Keith Haring was done without payment as a gift to entertain the children at the Hôpital Necker.

A scandalous Art Nouveau collaboration that set Paris all atwitter at the turn of the century.

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

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

The popularity of Sherlock Holmes led to the creation of his fictional address, turning the orderly London street numbers askew.

Once designed as the entrance to Buckingham Palace, this structure was later relocated and stands as a victory arch.

The next-door homes of two very different musicians, George Frideric Handel and Jimi Hendrix.

Shiny Brutalist box commemorates a pioneer of electricity and houses a railway transformer.

At the center of London’s oldest roundabout stands an obelisk that was erected in 1771, but spent several decades elsewhere.

The pretty iron lamp is a reminder of the architecture underneath London's streets.

Colorful murals by Jean Cocteau hide within this peaceful London sanctuary.

At the top of the hour, figures of the London department store's two co-founders emerge and bow to each other.

Claiming to be the oldest hat store in the world, this historic haberdashery had a hand (and a head) in the creation of the Bowler.

Originally meant to hold a statue of King William IV, this support sat empty for years. Today, it hosts a rotating cast of public artwork.

The bronze uniforms commemorate the vital role of women during World War II.

A haunting monument dedicated to the Royal Naval Air Service and the Fleet Air Arm.

This ancient Egyptian obelisk still bears the wounds of World War I.

The commemorative stone column conceals a secret laboratory.

An "inside out" building in the historical center of Paris, featuring Europe’s largest modern art museum.

A visionary precursor to the Internet made of index cards.