Nine centuries-old fortresses guard the walls of this medieval Romanian city.

Graffiti from the 16th and 17th centuries cover the walls of this part of the Tower of London.

This fairytale inspired, warped building houses restaurants, shops, and a radio station.

Catacombs turned marketplace.

This one has sailed five times as far as Sir Francis Drake's famous ship.

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

Hauled from the water's depths, Henry VIII's flagship is preserved in this capsule-shaped museum.

Follow the original medieval paths that wind through this intriguing section of the city.

It's possible to walk inside one of the largest Neolithic tombs in Britain.

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

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

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

This classic restaurant features a gorgeous mirror-clad room.

A slice of central Asia in the middle of Berlin.

Started as a kitchen garden, now the second largest botanical garden in the world.

A fire once nearly devoured this gorgeous 14th-century Gothic cathedral.

London's amazing modernist public square that never was.

Richard III supposedly disposed of his nephews' bodies here in an effort to seal his claim to the throne.

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

On October 17, 1814, a 15-ft. wave of beer ran rampant through the streets of London.

Something's watching you.

A tribute to the Polish insurgents who fought in the failed attempt to end their city's Nazi occupation.

A statue honors the children who fought Nazis in Poland.

The most visited, and possibly most controversial, museum in Germany.