An underground nightclub helped spark a "Singing Revolution."

This medieval Estonian tower provides access to a series of tunnels that have been home to soldiers, punks, and fine art.

These plaques found across Warsaw commemorate the sites where executions or battles took place during the German occupation.

A cluttered and astounding collection of antiquities and curiosities.

Lovers proclaim their unbreakable bond by leaving their names on locks fastened onto the Shoreditch fence in East London.

Hackney's newest private museum and natural curiosity shop.

A series of carved figures that scandalized British society.

What started as a way to address damp basement walls turned into a house filled with intricate hand-carved designs.

Collection dedicated to brands, packaging and advertising.

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

Repository for more than 22 million pickled specimens.

This massive collection of British military artifacts includes the heartbreaking personal letters of the men in the trenches of WWI.

This informal museum is a magical trove of anonymous art collected from car boots and flea markets.

The fierce beast perches atop a pedestal marking where the historic City of London gates once stood.

A glorious pub known for a spiteful printing feud and its famous typeface lost—then found—at the bottom of the Thames.

A statue marks the exact spot where The Boy Who Never Grows Up made his first literary appearance.

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

A 2000-year-old Roman amphitheater lies just below Guildhall Yard.

One of the world's largest collections of pathological specimens.

A historic London pub with prison cells in the cellar and a "spy room" on the second floor.

A historic house left in "dramatic still life."

A vast overgrown cemetery, once known as one of London's "Magnificent Seven."

Legend says these colorful, invasive residents are the descendants of birds released by Jimi Hendrix.

Children's hospital in London that operates on royalties received from Peter Pan, which J.M. Barrie signed over in 1929.