Thousands of coffin-like pillars make up this controversial Holocaust memorial.

Cold war icon and onetime "hole" in the iron curtain.

A fascinating insight into daily life in the Eastern Bloc.

One of downtown Berlin's last reminders of its Communist past.

This former “ante-chamber to the guillotine” has been refurbished to illustrate the brutal history of French justice.

A horde of stray cats rule in this secluded Parisian cemetery under a bridge.

Eighty million natural history specimens call this gargantuan museum home.

Mary Kelly was last seen here before she was murdered by Jack the Ripper.

Six ravens are kept captive (but well-fed) at the Tower of London to prevent the fall of the Crown.

The watery entrance for condemned prisoners heading to the Tower of London is still visible along the Thames.

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

The curios of pharmacist and collector Henry Wellcome.

Since 1874, this macabre collection has developed into a museum devoted to Scotland Yard's mementos of dastardly deeds.

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

Italian cave with exceptional acoustics and an unsavory history.

An Italian ghost town that fought obscurity, until a mysterious illness brought it to its knees.

2300-year-old Roman road connecting the empire.

A treasure trove of Renaissance-era funerary art in a Roman church built on top of Nero's grave.

More sculpture than building, this architecturally significant temple was built on the spot of Saint Peter's crucifixion.

This ancient Roman prison is decorated with an upside-down cross not as blasphemy but as saintly tribute.

The crypts of Capuchin friars decorated with the bones of over 4,000 friars, including an entire "crypt of pelvises."

Installed in an act of one-upsmanship, the annual sundial in this church is also a symbolic victory for the Gregorian calendar.

This aging storage facility is the world's largest brick warehouse.

Created as a punny statement about genetic engineering this monstrous hybrid statue has become a beloved icon.