A tribute to the Polish insurgents who fought in the failed attempt to end their city's Nazi occupation.

The former Nazi concentration camp stands as a museum to remember this dark chapter in European history.

This snug medieval lane is one of the narrowest streets in the world.

A medieval church built up to defend its village.

This communist behemoth is the heaviest building in the world and a legacy of a brutal regime.

This black sand beach was crafted from volcanic explosions including the historic Minoan eruption.

Heralded as the world's first theater, these ruins are often overlooked as they reside in the shadows of the Acropolis.

Underneath one of the region's most historic roads lies the home of Plato's successor.

A preserved portion of an ancient Athens barrier is displayed in a hotel basement.

According to legend, this ancient column contains healing properties.

The ruins of an ancient fortification wall sit in front of and underneath this boutique hotel.

This seaside sanctuary was once one of the most important religious sites for women in ancient Greece.

The oldest cemetery of modern-day Athens blends the modern and ancient worlds.

See massive fossils that are over 200 million years old in northeastern Arizona.

Wedding chapel's mysterious spiral staircase said to be miraculously constructed.

The folks at the Devil's Rope Museum want you to get hooked on barbed wire history.

A preposterously luxurious hotel with gold-plated iPads, Rolls Royce chauffeurs, and a staff that trains by watching "Downton Abbey."

The decaying remains of a once-luxurious Soviet spa town.

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

This fairytale castle was built as a show of power but was nearly torn down thanks to its history of torture.

The tallest church in Mechelen might have been the tallest in the world if not for a lack of funds.

Founded as a refugee camp, now a popular tourist spot.

The ancient heart of Tunis is an enormous maze of narrow streets and alleyways.

These ancient ruins hide in plain sight next to a dessert shop.