Philadelphia boasts one of the best — and most often overlooked — traditional Japanese gardens in North America.

A toxic ghost town sitting atop a massive coal fire.

This tribute to the fictional detective stands at the famous literary character's address.

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

This once-controversial and slightly confusing statue of Achilles was built out of captured cannons.

A memorial for public executions that dates back to the 14th century.

The "beautiful" equation predicting the movement of all electromagnetic particles is engraved in front of Newton's tomb.

At almost 1,000 years old, this is the oldest known door in all of Britain.

These wire animal sculptures commemorate the exotic inhabitants that once called the Tower of London home.

The commemorative stone column conceals a secret laboratory.

Its collection includes a broad array of social, geographic, graphic design, and political history.

The rose garden in Regent's Park where Pongo and Perdita met for the first time in Disney's "101 Dalmatians."

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

Giant, friendly pelicans in Central London, the most unlikely of places.

London's last remaining public soapbox site has seen speeches from Karl Marx, Vladmir Lenin, and George Orwell.

Abstract dinosaur models in London.

A statue marks the exact spot where The Boy Who Never Grows Up made his first literary appearance.

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

Scattered throughout London are ancient remnants of the city's former bounding wall.

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

The remains of Crystal Palace Great Exhibition of 1851.

A 2000-year-old Roman amphitheater lies just below Guildhall Yard.

Hear the quietest sound from across the dome.

This London pub hides a peculiar secret: a recreation of the rooms shared at 221b Baker Street by Sherlock Holmes and Dr. Watson.