The world of the ancient Celtic civilization explained through a bewitching 11 acre garden.

This floating garden in the sky is straight out of a fairy tale, but the real thing is nothing short of magical.

A tiny microvalley etched into the side of Knocknarea Mountain hides another world.

The gorgeous library at Trinity College is home to remarkable treasures of Irish identity.

The bridge is a secret gallery of discarded gum that has been transformed into miniature masterpieces.

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

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

A kaleidoscopic warehouse-maze of handmade neon signs.

This churchyard arbor is surrounded by hundreds of gravestones placed there by author Thomas Hardy.

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

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

A subterranean ice warehouse that has lain hidden beneath central London for over a century is now open to the public.

Banksy gives themself artistic license with this piece of London street art.

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

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

An unsanctioned shrine that sprung up outside the late singer's home is causing a stir in London's Highgate neighborhood.

This London marker celebrates the spot where the world-famous English band was founded.

The medieval woodcut-style artwork chronicles life in medieval London.

It celebrates a very stinky task and salutes London's fatberg-vanquishing team.

Sculptor Antony Gormley used chaos theory and fractal growth to design his tallest creation.

A mysterious carving from 17th-century London seemingly depicts a young boy sitting on a bread basket.

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

The commemorative stone column conceals a secret laboratory.

This unique bridge curls up like a caterpillar to let boats pass and then unfurls again to span a small canal.