An underground network of massive stone arches and their skylit vaults support ruins of portico structures above.

This arch granting triumphal entrance into Antalya was designed to honor the emperor's visit.

This crumbling medieval basilica once attracted pilgrims by the thousands to collect a miraculous dust that formed above the saint's tomb.

Carvings in Turkey's Marble Road may have directed ancient Romans to a hidden brothel.

The ancient latrines of the Greeks, in all their public glory.

The best-preserved ancient theater in the world.

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.

While not Turkey's deepest underground city, this subterranean redoubt is the largest.

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

A surprising and unconventional mosque hidden in the subsoil of Istanbul.

This historic hotel preserves many treasures from its heyday hosting passengers on the Orient Express.

This former Imperial summer home was the venue for a royal slap that once echoed 'round the world.

This half-forgotten fortress was constructed by the Ottoman conqueror of Constantinople.

This column celebrates Rome's victory over the Goths, and may be the oldest Roman monument in Istanbul.

Ancient serpentine sacrifice holder that has stood the test of time.

A fountain standing as a testament to a doomed alliance.

Climb a steep hill in 90 seconds on the second-oldest urban subway in the world.

A gorgeous, Gaudí-esque stairway constructed in the city of Istanbul by a prominent Jewish family.

An Art Nouveau gem hides beneath the layers of city grime obscuring this once-magnificent building.

The most metal church of all time was built in record time because of an international, pious pissing contest.

Step back in time and witness the fall of Constantinople.

This remarkably well-preserved Egyptian plinth is pretty well traveled for a giant piece of stone.