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

Preserved portions of Athens's ancient defenses are on display in a subterranean parking garage.

A tiny Greek Orthodox church from the Ottoman era hides on a busy city street.

Where commuters walk through remnants of an ancient Greek necropolis.

This small 16th-century church in Athens is almost entirely surrounded by a modern building.

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

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

Legend says it was constructed with the destroyed pillar of an ancient Greek Temple.

An ancient octagonal weather station named for the eight Greek gods of wind.

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

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

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

The only surviving choragic monument is a trophy awarded in 334 BC for the winning dramatic chorus.

These ancient ruins hide in plain sight next to a dessert shop.

A man's head is enshrined beneath a statue near the first building constructed for the modern Olympic Games.

This building displays the scars of the “Dekemvriana,” a dark time in modern Greek history.

According to legend, this ancient column contains healing properties.

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

This Ottoman-era church is hidden amid a busy tourist area.

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

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.

Underneath one of the region's most historic roads lies the home of Plato's successor.

These caves secretly held national treasures during World War II.