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

No one is sure if the world's fourth-largest diamond had been found in a rubbish heap or was pawned by Napoleon's mom.

1513 Turkish world map, full of European state secrets and snarky commentary.

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

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

A fountain standing as a testament to a doomed alliance.

Five sultans and their families rest in eternal splendor, teeming with overlooked beauty and drama.

This crucial gathering spot along the "hippie trail" still displays old notes between traveling beatniks and backpackers.

A marvel of Byzantine engineering under the streets of Istanbul.

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

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

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

Seven early Christians were sealed into a cave where legend has it they slept unharmed for centuries.

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

The alleged house of the Virgin Mary is tucked away in a park and nature preserve on Mt. Koressos in Turkey and is holy to both Catholics and Muslims alike.

A charming beach town in Turkey captures all the colors of the rainbow.

A deadly ancient portal to the underworld.

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

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

A sacred lake with thousands of sacred carp and a biblical history.

The largest Neolithic ruins in the world hide a notably clean prehistoric metropolis.

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

Mausoleum and Holy Seat of Antiochus I of Commagene.

This hunter-gatherer architecture is believed to be the oldest religious complex known.