A Bronze age settlement on the Greek island of Santorini might have been the inspiration for Plato's Atlantis.

These caves secretly held national treasures during World War II.

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

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

A Byzantine-era church hidden in a wooded area below the Acropolis.

Large collection from the 3rd millennium BCE.

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

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

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

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

An architectural gem nestled into a promontory overlooking a prehistoric landscape.

This unique architectural wonder is also tied to one of the 20th-century's most renowned writers.

The extravagance of Portugal’s "Pink Palace" resulted in a noble title being awarded to its owner.

A monument to the three wars that led to German unification towers within a Berlin traffic circle.

One of the world's heaviest musical instruments towers within a popular urban park.

On the Spree bank, discover one of the last reminders of a symbolic wall that divided, and was torn down by the people.

This ship offers visitors the chance to spend the night aboard a former floating hospital for fishermen.

This impressive rupestrian engraving dates back to the Upper Palaeolithic period.

An 11th-century medieval castle cascades over the town of Numão.

Come for the bread-themed puppet show, stay for the buffet.

Nestled in the mountains of Portugal is a tiny village made almost entirely of schist.

This castle has links to Portugal’s founding and struggles for independence.

This giant sculpture made of trash is a critique of society's wastefulness.

A stunning 18th-century site where pilgrims ascend by a series of punishing stairs only to return via funicular.