Dedicated to the American general whose reply to a German demand for surrender was simply "Nuts!"

This bunker in northern France was built by Nazi German forces with the intention of launching up to 50 V2 rockets at London each day.

Now overgrown, these anti-tank barriers from World War II are sometimes called "dragon's teeth."

In the city forest of Augsburg are oval, artificial ponds formed from a World War II bombing campaign.

Deceased nuns were placed on stone chairs to decompose, while the surviving nuns prayed near the lifeless bodies.

A memorial to the soldiers who died in the bloody battles to control Verdun in World War I.

The defensive tower was built centuries ago to warn locals of Berber pirate attacks.

There was a top secret plan during World War II to seal a group of soldiers inside the rock.

A southern Swedish island is home to the last ERSTA artillery battery, meant to protect the shoreline during the Cold War.

Built by a king and rebuilt by an emperor, this aqueduct transported water for 1,200 years to this ancient Mediterranean hub.

A magnificent waterfall is also home to the remains of a Roman hydraulic engineering system.

This mysterious ancient arch is hidden in the forest of Simbruini Mountains Regional Park.

Ever loyal to Roma, the small village of Albe in the Abruzzo region carried on until an earthquake did it in.

This Roman underground canal was the longest tunnel ever built until the late 19th-century.

The only visible remains of this ancient Greek underground temple is its roof protruding from the earth.

This Roman archeological site is hidden amid a 1930s housing estate.

Home to the ancient Roman temple of a lesser-known Celtic god that inspired J. R. R. Tolkien and H. P. Lovecraft.

This railroad track was so secretive that it was omitted from all maps.

The United Arab Emirates's biggest and oldest fort pays homage to a lost era.

This triumphal arch celebrating the Sun King's conquest of Lille is a masterpiece of military architecture.

A section of the long chain that blocked enemy ships from entering Constantinople.

Inside this McDonald's you can dine on your Big Mac and fries next to a 2,500-year-old Roman wall.

This ancient Roman arch misled treasure hunters for centuries.

This one-of-a-kind Roman arch is not actually dedicated to the god Janus.