This area belongs to the eastern half of ancient Athens which extended from the southern foothills of Mt. Lykabettos (Queen Sophia's and University Avenues) to the sanctuary of Olympian Zeus and the east side of the ancient fortifications (near the ministry of education, as far as the eastern edge of the National Garden or Iroidou Attika St.). The excavation for Syntagma Station was conducted on the west slope of the low hill that existed on the side of the Greek Parliament, the top of which was leveled in 1836 when King Otto's palace was built there.
This is a privileged location, with plenty of water from the two rivers that flowed through it, The Illisos to the south and the Eridanos to the north, a feeder of which came down from Mt. Lykabettus, passed under the esplanade of the Unknown Soldier, crossed Amalia's Avenue diagonally and via Othonos, Mitropoleos and Hadrian streets reached the keramicos (potters quarter) where is is (barely) visible today.
In antiquity the area was extra muros, that is outside the walls of the city of Athens, and specifically outside the east branch of the ancient fortification which passes today close to the Ministry of Education. It was therefore natural that cemeteries and workshops were located here. Its southern part, where the excavation in the Zappion shaft was conducted was an idyllic landscape, watered by the river Illisos and with lush verdant vegetation. Many sanctuaries were founded hereabouts from earliest times, while it was a place of residence and burial too. The east edge of the area where the excavation for the National Gardens shaft was conducted was also extra muros in antiquity and close to the road artery to the demes of Mesogeia. From early times a large cemetery developed here. However, with the eastwards expansion of Athens during the reign of the Emperor Hadrian, the area of Syntagma Sq., The National Gardens and Zappion was included in the layout of the city and indeed formed a wealthy quarter, since new sanctuaries, private and public buildings and bath-houses were built here.