A marvel of Byzantine engineering under the streets of Istanbul.

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

When construction began on this hotel, developers were surprised to find the ruins of an ancient civilization.

The partially submerged ruins of a white marble quarry used in ancient Greece for over 1,200 years.

This slumbering beast honors the Bavarian soldiers who died in Greece during a 19th-century typhoid outbreak.

These ruins of a sacred Ancient Greek temple stand next to a luxurious modern resort.

This historic structure has been used as a mosque, a barracks, a prison, a school, and a bakery.

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

This beehive tomb built for royalty sat hidden for over 3,000 years.

According to legend, this cavern holds the passage that Persephone used to travel to and from the underworld.

This 200-meter-high waterfall marks the site of Achilles’s immortal baptism at the mouth of the River Styx.

This town named for the ancient God of War is home to fewer than a thousand people, but it's the birthplace of the Greek Revolution.

A small island with shimmering pink sands, home to loggerhead turtles and rare plants.

This abandoned Greek island was the last active leper colony in Europe.

The ruined doorway is a portal to the building's turbulent and torturous past.

Where commuters walk through remnants of an ancient Greek necropolis.

One of the largest single-span stone-arch bridges in the Balkans looks like something straight out of a fairytale.

The ruins of this monumental city founded by the first Roman Emperor are strangely overlooked by most travelers.

A two thousand year old brothel uncovered in Northern Greece.

Poseidon? No one seems to know.

Cave on extinct volcano, once home to famous mathematician Pythagoras.

Two churches shoot bottle rockets at each others' bell towers in an unusual Easter celebration.

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

The ruins of an ancient Roman tomb hidden in the basement of a trendy clothing store.