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

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

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

This ornate Victorian marketplace was the setting for Diagon Alley and the Leaky Cauldron in the Harry Potter films.

Kings Cross Station pays tribute to its role in Britain's best-selling book series.

This series of underground chambers contains Europe's largest subterranean lake that is slowly drained each day.

Hidden beneath the streets of London is a secret subway that only carried mail.

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

London's creepiest cemetery was once the site of dueling magicians and mobs of stake-carrying vampire hunters.

A hermit's tiny cell built into the cliffside that saved him in South Pembrokeshire.