Ancient paintings known as the "Sistine Chapel of Cave Art."

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

The world's first zoo for microbes collecting the horrible and wonderful things living on and around us.

The perfectly preserved underground rooms where Churchill plotted the war against Germany.

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

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

Hear the quietest sound from across the dome.

A historic house left in "dramatic still life."

Thanks to modern navigational tools we now know that the true prime meridian runs through a park next door.

An artistic tribute to the famous singer, just around the corner from where he was born.

This hidden green space is the city's second largest conservatory.

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

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

Large-scale contemporary artworks tower over fields and lurk in forests around a Jacobean manor house.

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

These phallic stone spires once served as Tolkien's Paths of the Dead.

A peace symbol in Northern Ireland is among the world's largest hedge mazes.

The highest peak in Northern Ireland is topped with a stone tower and haunting burial mounds.

The oldest pub in Ireland may also be the oldest surviving bar in the entire world.

Mountain where Jesus was first tempted by the Devil.

Week-long block party becomes a competition for the best decorated street.

This semi-secret storybook hedge maze is also the oldest garden in the city.

This miniature Paris, built out of trash, is one man's two decade labor of love.

A tiled, multi-level garden of survival in Lyon.