Introduction to the Tombstone of the Unknown Soldier: The Tombstone Monument of the Unknown Soldier was built in 1928. Behind the monument is the Congress Chamber, which is now the Supreme Parliament Hall of Greece. In the center of this stele is carved a warrior wearing armor and holding a shield, lying on the battlefield. In order to regain sovereignty from the Turks who ruled Greece for four hundred years, Greece sacrificed many warriors, so the Greeks built this monument to comfort the souls of these unknown heroes. Soldiers perform a changing of the guard ceremony every hour, and this is also the time when tourists take most photos.