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

View the ancient remains of buildings and the ancient "River of Hades" before hopping on a train.

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

This small chapel holds the mummified heart of one of the heroes of the Greek Revolution.

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

A crushed gate and giant bronze head serve as a reminder of Greece's fight for freedom.

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

This graffitied 19th-century building was a prototype of European industrial architecture.

Scars of this building's past life as a violent prison still cover its walls.

These caves secretly held national treasures during World War II.

The site where hundreds of Greeks were tortured by the Nazi secret police is now a cosmetics store.

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

This small museum once served as a royal hunting pavilion for King Otto Friedrich Ludwig.

Gladiators once walked this ancient, subterranean passage.

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

Where commuters walk through remnants of an ancient Greek necropolis.

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

The oldest cemetery of modern-day Athens blends the modern and ancient worlds.

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

This mystical orb covered in strange symbols is thought to have been used in ancient Greek magical rituals.

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

1,500 Commonwealth servicemen of World War II are buried or commemorated in this cemetery.

This stone tower was built to protect Crete from incoming pirates.

This famous archeological mystery may be an ancient example of movable type.