Children's playground hidden under a big pink and blue cap.

An archive of ceramic eggs painted to record clowns' personal makeup designs.

A makeshift shrine to the late rock star is still kept up on the nondescript façade outside 1 Logan Place.

Remnants of a Victorian garden feature sitting in public woodland.

A little slice of Japan and its aesthetics in London's Holland Park.

A tongue-in-cheek arcade where the games are based on everyday life.

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

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

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

This shop and gallery is a modern-day cabinet of curiosities, unassumingly positioned along an urban thoroughfare.

This walkway is so narrow it needs its own light to stop pedestrian traffic jams.

This collection of over 50 murals celebrates Brussels' rich history as the self-proclaimed home of the "comic strip."

The curious underground history of keeping Paris clean.

Egyptian Revival movie palace abandoned for decades and restored in 2013.

One of the oldest medical collections in Europe focusing on rare surgical instruments.

A 300-year-old tea shop that brought tea to the English people, not to mention the Queen herself.

A kaleidoscopic warehouse-maze of handmade neon signs.

Paris' fabled purveyor of exotic taxidermy and natural history curios.

Only museum in the world devoted to bookbinding and book arts holds a permanent collection representing five centuries.

Lavish royal estate punctuated with heated greenhouses.

The largest collection of handbags in the world, the oldest of which were used to carry Bibles, primarily by men.

A floating cat sanctuary on an Amsterdam canal.

An Amsterdam street lined with antique shops each one dedicated to a different obscure collection.

The world's only museum devoted to the wonders of fluorescence.