Ancient Athens had its own “Great Wall” like China’s that started from Mount Aigaleo and reached Parnitha Mountain, built to stop raids during the Peloponnesian War (431-404 BC).
The great stone structure that is 4.5 kilometers (2.8 miles) long connects the two mountains in order to block the passageway between them. It was built about 2,500 years ago, during the Peloponnesian War, to stop Spartans and their allies from attacking Athens.
It was the passage that Thucydides called “Kropeia” and was the main invasion passage the Peloponnesian forces used to attack Attica and Athens.
In the 19th century the locals named the wall “Dema” or “Desis” because it looks like it “ties” the two mountains together.
The stone fortifications start from the northeast of Aspropyrgos and end around 2.5 kilometers west of the Ano Liosia suburb, where the narrow passage between Aigaleo and Parnitha Mountain is formed.
History of Dema Great Wall
The Dema Great Wall of Athens was around 4.5 kilometers long and was built to protect the strategically important pass that led from Acharnes to the Thriasian Field. From there the Spartans, under the command of King Archidamus, invaded the Acharnic Field in 431 BC, the first year of the Peloponnesian War.
The wall was built of roughly hewn polygonal boulders without binding material, with the gaps filled with smaller stones. The fortification is not a single unit, consisting of multiple small, overlapping sections, creating narrow corridors and entrances with sloping ramps behind them for easy access to its flat top. The thickness of the walls varies between 1.5 and 2.8 meters (4,92 to 9.12 feet).
Two openings that seem to have served as gates are found approximately in the middle of the Dema length. The northern one led to Oea and the southern one to the Thriasian Field. Perhaps there was a third gate. At a distance of 225 meters east of the wall, a Rear Wall has been identified, a low dam made of claystone about 120 meters long, which runs parallel to the main Dema.
Its total length has been calculated at 200 meters. It aimed to block enemy troops towards the plain of Ano Liosia, the eastern side of which is blocked. The Rear Wall was built, in all probability, at the same time as Dema or a little later.
However, the two fortifications appear to be part of the same building plan, as the Rear Wall reinforces the Dema at the point where the latter is more easily accessible, and therefore vulnerable, due to the smoothness of the ground.
Reconstruction of the “Great Wall” of Athens
Although the dating of the reconstruction of the Dema Great Wall of Athens is quite problematic due to the lack of data, most archaeologists place it in the 4th century BC.
In fact, they associate it with the Boeotian War (378-377 BC) considering that it was built to function as a bastion of a large army, which would be defended by numerous hoplites, horsemen, and peltasts.
Many historians emphasize that the Great Wall was not built to intercept enemies moving towards the city of Athens, but to delay them. Thus, the Athenian army, informed of the enemy’s advance, would overtake the attackers before they reached the city. Moreover, the Dema would not allow a large army to pass through in full formation, thus facilitating sabotage, especially in the rearguard.
So far, no efforts have been made on behalf of the Ministry of Culture or other agencies to restore and promote the Great Wall of Attica site.
Today, a railway line and a highway pass through this passage, connecting the northern suburbs of Athens with the Thriasian Field.