This 15th-century island fortress later served as home to the executioners no one wanted to live near.

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

Where commuters walk through remnants of an ancient Greek necropolis.

Giant marble phalluses on the sacred island of antiquity.

Replicas of Apollo's leonine stone guard cats still line a sacred row in Greece.

A sharp sculpture made of thousands of pieces of jagged glass.

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

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

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

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

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

A 2,000-year-old computer demonstrates remarkable engineering and astronomical precision.

Historic medieval fortified city in southwest France.

This salt marsh in Southern France is as pink as the flamingos that inhabit it.

Sky ships, planes, and portraits left as unique tokens of hope and thankfulness.

This ancient theater was once the home of fierce gladiatorial battles.

A beautiful bronze statue of the greatest fossil hunter of the 19th century.

A local museum honors the overlooked discoveries of Mary Anning, one of the first professional fossil hunters.

An iconic location along the Los Angeles River where countless movie scenes are filmed.

Concrete strongholds stand guard over the Golden Gate.

A Hawaiian stairway to heaven—that you can't climb.

This saltwater swimming pool, which is the last of its kind in the United States, is slowly crumbling within sight of multiple high-end beachside hotels.

This coastal cavern is associated with the Hawaiian god of creation.

A priest with no formal artistic training used basic house paint to create gorgeous religious scenes inside this historic church.