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

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

The watery entrance for condemned prisoners heading to the Tower of London is still visible along the Thames.

Two plaques commemorate the site of Shakespeare's first theatre.

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

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

After nearly 60 years, there's still a bear at Paddington Station looking for help.

In this cobwebbed old operating theater, you can practically hear the screams of the unanesthetized patients.

Hear the quietest sound from across the dome.

An incarceration museum on the spot of possibly the oldest prison in England.

An unusual round church in London with a Templar past.

The quaint little store that is said to have inspired a famous Dickens novel was only given its name after the book was released.

Eighty million natural history specimens call this gargantuan museum home.

Banksy gives themself artistic license with this piece of London street art.

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

The perfectly preserved underground rooms where Churchill plotted the war against Germany.

Kings Cross Station pays tribute to its role in Britain's best-selling book series.

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

This ornate Victorian marketplace was the setting for Diagon Alley and the Leaky Cauldron in the Harry Potter films.

This impressive Boston holy house is the American mecca for Christian scientists.

An interesting decoration on this historic site, this weathervane comes with as many legends as it does questions.

A former waterfront market is now in the center of town due to some interesting Boston engineering.

Historic Hull Street was actually the first street with a proper name in the Boston area.

This monument on Breed's Hill proves that one of the most famous battles of the Revolutionary War is misnamed.