This enchanting Victorian estate was home to the world's first hydroelectric power generator.

One of the few standing Roman lighthouses and a labyrinth of tunnels are a couple of the secrets at this historic castle.

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

Abstract dinosaur models in London.

The remains of Crystal Palace Great Exhibition of 1851.

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

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

The site of London's first coffee house has been serving refreshments of one kind or another for 360 years.

This one has sailed five times as far as Sir Francis Drake's famous ship.

Rebuilt remains of a temple to Roman god Mithras.

Hear the quietest sound from across the dome.

A friendly pub with a sordid past in cock fighting.

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

An unusual round church in London with a Templar past.

Wedged between two buildings at the Great Ormond Street Hospital is this secret music installation.

Traveling collection of amazing automata.

Claiming to be the oldest hat store in the world, this historic haberdashery had a hand (and a head) in the creation of the Bowler.

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

This luxury shopping lane has been protected by its own tiny police force for over a century.

This collection of illusory paraphernalia has been culled from the history of London's premier magician's club.

English antique dealers with a taste for the unusual.

Catacombs turned marketplace.

A clock designed to run with perfect accuracy for 10,000 years.

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