Monasteries on rock pillars, once accessible only by frayed ropes.

A tribute to an explorer and naturalist often overlooked by history.

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

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

One of the few remaining examples of 19th-century London’s attempt to clean up its reputation.

A statue of the legendary Celtic warrior queen who fought the Roman invaders stands in one of the cities she once destroyed.

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.

London's smallest police station is barely the size of a phone booth.

This coffee shop lies hidden beneath a historic church.

A student driver's nightmare.

Eighty million natural history specimens call this gargantuan museum home.

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.

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 may be the last of London's wooden pavements, which were once a common sight in the city.

A museum that chronicles the history of the Nuremberg Trials for Nazi war criminals in the building where the trials were once held.

This abandoned coliseum was intended to be a grand Nazi rallying ground before it was halted at the end of the war.

A public work of art that also provides some relief from the summer heat.

A whimsical bridge adorned with decorative dragons.

This bustling Italian plaza is built on the ruins of an ancient Roman amphitheater.

Fortified medieval tower house with lovely roof garden.