The only visible reminders of an elaborate engineering project that kept the tower from reaching the tipping point.

Two stone columns flank the grand Venice square, but there were supposed to be three.

Where Venice's gondolas go for a tune-up.

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

This memorial museum chronicles the apocalyptic destruction of the First World War.

A rare example of World War I trenches from the British front.

In the shadow of a former battleground, the resting place for nearly 2,000 soldiers who died in World War I.

In an area where the remnants of WWI are discovered on a regular basis this preserved frontline trench may be the most amazing.

The site where one of the most famous poems of World War I was composed is preserved to honor the legacy of the work.

Remains of the artificial harbours invented for the Allied invasion of Normandy can still be seen at sea.

A memorial to the nearly 10,000 American soldiers laid to rest on the beaches of Normandy during WWII.

This enormous "cloth of the conquest" depicts the Norman invasion of England in mind-blowing detail.

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

There's an exclusive Beefeaters pub hidden in the Tower of London.

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

An unusual round church in London with a Templar past.

Claiming to be the oldest hat store in the world, this historic haberdashery had a hand (and a head) in the creation of the Bowler.

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

This little-known hero has been protecting "The Fens" for close to 400 years, and now from its most powerful challenger yet: climate change.

A remarkable medieval structure born from a 14th-century disaster.

Local legend says Isaac Newton built this footbridge without any screws, bolts, or nails.

Named after a lodging site that existed nearby, a bridge has existed at this location since 1455.

This stunning concert hall has become a symbol of Iceland's national recovery.

One of the tallest buildings in Iceland, and perhaps, the most visually impressive.