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

A plaque hangs near the execution place of the Scottish Independence leader famously depicted in "Braveheart."

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

A naturally mummified 2,000-year-old man.

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

19th-century scientists would make the pilgrimage here to verify the precision of their measuring sticks.

The John Snow Memorial marks the epicenter of London's 1854 cholera epidemic.

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

A mysterious pair of mice eating a piece of cheese is London's smallest public sculpture.

An alleyway plaque is all that remains of the independent Texas' envoy that forgot to pay their rent for over a century.

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

A 1,215-foot tunnel transports pedestrians beneath the River Thames.

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

An easily overlooked stretch of ornate window fronts and gaslight lamps that could be right from the pages of Dickens.

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

A 300-year-old tea shop that brought tea to the English people, not to mention the Queen herself.

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.

For a few short weeks in spring, this hiking path becomes a daffodil paradise.

The "little Sistine Chapel of Luxembourg" is in the smallest village in the tiny country.

A Roman water tunnel still flows 2,000 years on.

This modest monument marks the only point of intersection between longitude and latitude in the Grand Duchy of Luxembourg.

A never-finished memorial to the heroes of the Napoleonic War has become "Scotland's Folly."

The patron saint of cats founded this stunning Romanesque church in the 7th century.