A tour of underground Berlin takes you through WWII air raid shelters and tunnels used to smuggle people out of East Germany.

A whimsical and twisted animatronic monster tour beneath the streets of Berlin.

A slice of central Asia in the middle of Berlin.

This futuristic German spa allows visitors to float in a pool of salt water while zoning out to underwater techno.

This off-beat, quirky communism-themed bar isn't afraid to poke fun at its history.

A five-story homage to tea times past.

This secret garden has bloomed into London's most unique hub of urban creativity.

Historic cuisine meets fine dining in a hotel-restaurant overlooking Hyde Park.

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

More than a million titles fill the labyrinthine shelves of this prestigious private library.

The lab where the scientist made his groundbreaking discoveries is preserved on the basement floor of the Faraday Museum.

Charles Babbage's proto-computer, painstakingly brought to life.

This 1920s Dutch barge is now a floating bookstore.

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

An easily overlooked stretch of ornate window fronts and gaslight lamps that could be right from the pages of Dickens.

The "shampooer of kings" who opened London's first curry cafe was a celebrity in the 19th century, but is all but forgotten now.

This 19th-century pub features stained-glass windows celebrating Victorian-era "champions."

This pub was 238 years old when it decided to revamp its image: It started serving Thai food.

Classic game cookery takes center stage at what's widely considered London's oldest restaurant.

Drink your espresso at a Victorian-era urinal in this underground-restroom-turned-coffee-bar.

Originally built for London’s cab drivers, this bright green hut now serves anyone a hot drink or meal.

A decommissioned tube carriage within a London museum hosts a regular pop-up supper club.

Since 1887, this old-school shop has stacked its shelves with extraordinary coffees and teas.

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