A marvel of Byzantine engineering under the streets of Istanbul.

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

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

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

150 or so scrounged-up lamps, chandeliers, and lanterns light up this alley in central Athens.

A Byzantine church containing the holy remnants of three saints sits atop the site of an ancient temple.

What once sat in the world’s spotlight is today a largely disused ghost complex.

This gem is often wrongly overshadowed by the larger, newer Metropolis church in Athens.

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

Giant marble phalluses on the sacred island of antiquity.

This ancient hydrological marvel is now the base of a modern outdoor cinema.

The Cycladic architecture makes this Athens neighborhood feel like an island paradise hidden in the shadow of the Acropolis.

Legend says this sacred tree was a gift from goddess Athena.

This ancient Greek place of assembly and marketplace is being revealed layer by layer below the modern Athens cityscape.

The hallucinogenic center of the ancient world.

This noble mash-up in eastern Luxembourg is part Medieval, part Renaissance, all castle.

The remains of an ancient city-state along the Silk Road.

This collection of several museums includes one of the oldest structures in Iceland.

The platform atop this verdant volcano was built with the help of a royal elephant.

This quiet island in the middle of a bustling city is actually a volcano dotted with Māori ruins.

Home to the unidentified remains of the 1979 Mt. Erebus Disaster.

A New Zealand communications tower stands as the tallest structure in the Southern Hemisphere.

A poignant memorial to remember the Australian nurses who lost their lives during the Second World War.

Taxidermy of the racing horse with a huge heart, who inspired hope in the Depression.