This ancient theater was once the home of fierce gladiatorial battles.

This modern French ossuary contains the jumbled bones of 130,000 WWI soldiers.

A moving memorial to the fallen and missing from WWI trenches.

A monument to the thousands of Canadian soldiers who died capturing the French ridge during World War I.

Looking strangely like Rome's Colosseum, this unfinished tower has dominated the skyline for over 100 years.

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

Tucked away in the Tower of London is the weapon once used to execute high-profile prisoners.

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

These mysterious Viking chess pieces spent centuries hidden on a remote Scottish island.

Once designed as the entrance to Buckingham Palace, this structure was later relocated and stands as a victory arch.

A island reachable by a causeway at low tide is possibly one of the earliest Western European locations to be identified in text.

A medieval quay that was the Mayflower's final port of call before sailing for America.

A museum based on the collection of a Victorian family. Housed in a remaining Victorian villa.

In addition to escorting prospective couples to and from ballrooms, this lane was also a place for gentlemen to settle scores.

There are two dozen tanks just sitting in an open field in Lower Saxony.

A decomissioned facility where the German "Transrapid" maglev trains were once tested.

This copper-coated, multi-arched dome is surrounded by a moat and lights up at night.

Dozens of large-scale, creative, evocative curios from prominent artists dot the calm outdoor space around this major museum.

From a distance, this statue of an eagle looks like a giant chicken on a stick.

The oldest military monument in the United States.

This 16-foot, intricately detailed model of the Gearing-class destroyer has been called the most detailed model ship ever built.

This whimsical group of statues is a favorite of children who love to climb all over Lewis Carroll's beloved characters.

Elevated freight railway turned wildly successful urban park.

This sculpture by artist Fritz Keonig survived the 9/11 attacks and now stands as a monument to the victims.