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

A hidden treasure in London with a rich medieval history, and the resting place of many luminaries.

An unusual round church in London with a Templar past.

This charming colonial alleyway is one of the oldest continuously used residential streets in the U.S.

The somber sculptures commemorating Irish Famine on the river Liffey in Dublin.

The wooden telephone box hidden away in London's Piccadilly was the original prototype of the iconic kiosk.

A portly statue of a golden boy commemorates an unusual cause of the Great Fire of London: the sin of gluttony.

Installed at a chaotic intersection, this gave London traffic cops a place to hang their heavy woolen coats.

This London plaque marks the spot where David Bowie's famous alien made his debut.

A naturally mummified 2,000-year-old man.

The John Snow Memorial marks the epicenter of London's 1854 cholera epidemic.

London's smallest police station is barely the size of a phone booth.

The bar where "The Great Train Robbery" was planned was once a nexus of high society and low morals.

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

Puppet theater and museum holding a collection of more than 300.

Where once there was a train station bathroom, there is now this German burger joint.

On the Spree bank, discover one of the last reminders of a symbolic wall that divided, and was torn down by the people.

An abandoned NSA listening post on Berlin's "Devil's Mountain."

An eerie, derelict amusement park in Berlin.

A narrow passage next to a cafe leads to a courtyard exploding with murals, tags, and paste-ups.

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

Berlin's oldest surviving academic architecture hosted decades of animal dissections.

A slice of central Asia in the middle of Berlin.

A surreal museum of extraordinary industrial objects.