This plaque commemorates the call between Alexander Graham Bell and Thomas A. Watson.

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

There are many Byzantine-era churches still standing in Athens, but this is the only one with a 2,500-year-old column rising through its roof.

Large collection from the 3rd millennium BCE.

These caves secretly held national treasures during World War II.

Where commuters walk through remnants of an ancient Greek necropolis.