A small etching on the white marble parapet was written in runic script by a Viking mercenary.

The best-preserved ancient theater in the world.

The deepest underground city in Turkey was designed to protect 20,000 people behind massive stone doors.

A Turkish ghost town abandoned in a population exchange with Greece.

These tombs were built into the side of a mountain so that ancient angels could reach the dead.

Roman ruins top white travertine terraces formed by ancient hot springs.

A marvel of Byzantine engineering under the streets of Istanbul.

In this historic region, homes and churches are carved into ancient volcanic rock formations.

Known as the "Valley of the Moon," this Jordanian wadi is one of the most amazing desertscapes on Earth.

This exceptionally well-preserved ancient marvel also houses a small museum dedicated to Jordanian folk tradition.

Gladiators battle and chariots race daily in the ruins of a once-great Roman city.

An ancient capital city that dates back 3,000 years and harbors many surprises.

A more chill but no less fascinating version of the famous ancient archeological site.

The only quarter of the Old City not dedicated to a major world religion.

The maze-like transportation hub contains abandoned areas, derelict stores, and a resident bat colony.

This daunting 1st century fortress was purportedly the site of one of the most dramatic revolts of the Jewish-Roman wars.

On the cliffs of São Jorge in the Azores stand the remains of a lighthouse that was struck by a series of earthquakes.

A shrine-like museum entirely dedicated to soccer superstar Cristiano Ronaldo.

Bits of flat terrain surrounded by cliffs make one of the most beautiful landscapes in the Azores.

Eat the ultimate iteration of Portugal's most beloved pastry.

These small, triangular, colorful houses are a staple of Madeira Island.

As the highest point in the Mid-Atlantic range this stratovolcano offers spectacular views.

Europe's oldest still-operational tea farm also boasts a spectacular view.

A lush oasis full of vibrant plants and striking geometric displays.