An optical Illusion once believed to be an electrical phenomenon.

Now in ruins, this castle stood for centuries and saw a number of gruesome events.

These unique weather vanes honor Scotland's most famous bard and decorate this walkway.

Also known as “Robin Hood’s tree,” it became a famed location along Hadrian's Wall before it was cut down.

Abandoned for over 20 years, this Art Deco seaside swimming pool is a magnificent waste.

There were once more than five stones in this ancient monument.

This massive, 30-foot-tall statue of the famed Scottish knight overlooks a grassy knoll.

For decades, a bottle factory dumped their waste into these waters—now it's considered the best sea glass beach in England.

A morbid secret lies hidden within the beautiful walls of the Boston Athenaeum.

An unusual stone chair can be found on the banks of the River Wear, not far from Durham Cathedral.

These lamps were created to expel sewer gases after an event known as The Great Stink.

The 2,000-year-old pieces of metal are an ancient soldier's military discharge papers.

This library dates back to the late 17th century and was one of the first public lending libraries in England.

A monument with a strange legend involving a horse's tongue.

Take afternoon tea in a 17th-century almshouse.

Hundreds of years ago, this lion-shaped door knocker could help a person accused of a crime find temporary safe haven in Durham Cathedral.

A rather grand, but tiny, folly on the banks of the River Wear associated with a Polish count.

This platform is now a memorial dedicated to those who were deported during the Holocaust.

The world's first clock to use set theory as a measure of time required the invention of a new light bulb just to maintain its obtuse measurements.

The bunker where Hitler took his own life is hidden under this deliberately ordinary parking lot.

One of downtown Berlin's last reminders of its Communist past.

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

A fascinating insight into daily life in the Eastern Bloc.

Thousands of coffin-like pillars make up this controversial Holocaust memorial.