This life-size monument honors the legacy of a famous literary feline.

These marks in Myddelton Passage aren't your run-of-the-mill vandalism, and they weren't made by your typical vandal.

An unassuming London park is actually a pilgrimage site for modern clowns.

A subterranean ice warehouse that has lain hidden beneath central London for over a century is now open to the public.

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

This coffee shop lies hidden beneath a historic church.

One of the world's first dedicated bank buildings in the world is now the oldest one.

A plaque marks the house in Stockholm where the French philosopher René Descartes lived up until his death.

Stockholm's narrowest alley is barely over two feet wide.

Dine on food tied to Viking history and legend at this subterranean Stockholm spot.

It is said that each of the white stones in the red facade of this medieval house represents the head of a murdered Swedish noble.

A 130-year-old urinal is the oldest of Stockholm and perhaps all of Sweden.

An ancient Viking runestone hidden in plain view in Stockholm's old town.

Stockholm's tiniest statue is of a small boy looking at the Moon.

The last four extravagant street signs of London's historic banking street.

A Roman spa buried deep beneath the City of London.

The Great Fire of London and the regulation of one-way streets both started in this alley.

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 first ‘Harry Potter’ film.

This pump on the bad side of Victorian London betrayed a horrifying revelation about the water supply.

The barrel-made lookout from Shackleton's final ship is tucked away in the crypt of one of London's oldest churches.

A hidden treasure in London with a rich medieval history, and the resting place of many luminaries.

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

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