Before he was forced to flee the country under Nazi rule, Albert Einstein spent his summers in this custom-built lakeside house near Berlin.

Solar observatory doubles as a daring display of Expressionist architecture, much to Einstein's chagrin.

A quaint Russian village in the middle of a German metropolis.

Super-heavy Nazi architectural experiment.

A collection of abandoned typographic signs from Berlin and beyond.

The site where a plot to assassinate Hitler was planned—and its conspirators were executed—is now a powerful memorial to the German resistance during World War II.

Come stay at a live-in art installation.

Wedged between two buildings at the Great Ormond Street Hospital is this secret music installation.

The commemorative stone column conceals a secret laboratory.

A Roman spa buried deep beneath the City of London.

The barrel-made lookout from Shackleton's final ship is tucked away in the crypt of one of London's oldest churches.

19th-century scientists would make the pilgrimage here to verify the precision of their measuring sticks.

This 1920s Dutch barge is now a floating bookstore.

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

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

London's creepiest cemetery was once the site of dueling magicians and mobs of stake-carrying vampire hunters.

The sculpture of the deceased cockatoo flops atop its personal plinth.

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

Eclectic final resting place of the controversial explorer.

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

Scattered throughout London are ancient remnants of the city's former bounding wall.

An incarceration museum on the spot of possibly the oldest prison in England.

Remnants of a Victorian garden feature sitting in public woodland.

Artists have long been drawn to these atmospheric 12th-century ruins.