Famously misunderstood wonder of the ancient world

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

An unusual round church in London with a Templar past.

A hands-off space for graffiti artists to hone and display their skills.

One part local history, 99 parts gruesome haunted house.

The longest hedge maze in the world.

The curios of pharmacist and collector Henry Wellcome.

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

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

Several plaster noses are hidden in plain sight around London's Soho neighborhood.

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

A island reachable by a causeway at low tide is possibly one of the earliest Western European locations to be identified in text.

Hear the quietest sound from across the dome.

Catacombs turned marketplace.

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

A fantastic castle rumored to be the birthplace of King Arthur.

The signs of a long buried road can still be found hidden beneath a London sewer grate.

The anatomical-pathological collection of a man who changed surgery.

Eighty million natural history specimens call this gargantuan museum home.

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

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

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

The largest of London's subterranean rivers and once a mad, bad center of London life.

A historic London pub with prison cells in the cellar and a "spy room" on the second floor.