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.

Now in ruins, this abbey was the home of Tironensian monks for more than 400 years.

These magnificent city walls rise from the barren sun-baked Spanish plains like something straight out of a fairytale.

An ancient Egyptian temple in the middle of Madrid, Spain.

This massive monument was unveiled the day Kosovo declared independence from Serbia.

A futuristic, brutalist masterpiece that is also strangely prison-like.

A 11-foot former president stands on a Kosovo street that also bears his name.

This memorial park stands on the site of one of the largest mass executions of the Second World War.

A towering spire in the fortress of Kalemegdan honors the victorious armies of Serbia during their struggles against the Ottoman Empire.

A misnamed well, with a deep dark past.

A museum dedicated to the former country.

This exclusive resort has completely covered a tiny Balkan island in a 5-star warren of guest rooms.

Former military fort and site of untold horrors during WWII, this island may become the Adriatic's next luxury resort.

A tiny church on a man-made island in the Adriatic.

These historic defenses ensured the city within would survive hundreds of years of occupations, sieges, and invasions.

This World War I fortress is the perfect place to catch a Montenegrin sunset.

A beautiful mountaintop mausoleum devoted to a Montenegrin icon can't seem to make everyone happy.

This historic timepiece is thought to be the only public clock in the world that keeps lunar time.

The first mosque in the world to receive electricity.

Oriental bazaar in the heart of Sarajevo.

The place where World War I began.

This ironic war memorial thumbs its nose at a campaign of inedible humanitarian aid food products.

The haunting ruins of a military fortress turned astronomical observatory sit on a Sarajevo mountaintop.