The Pelasgic wall or Pelasgian fortress or Enneapylon (Greek: Εννεαπύλον; nine-gated) was a monument supposed to have been built by the Pelasgians, after levelling the summit of the rock on the Acropolis of Athens. Thucydides^[1] and Aristophanes^[2] call it "Pelargikon", "Stork wall or place". "Pelargikon" refers to the line of walls at the western foot of the Acropolis.^[3] During the time of Thucydides, the wall was said to have stood several meters high with a large, visible fragment at 6 m (20 ft) broad, located on to the south of the present Propylaia and close to the earlier gateway.^[4] Today, the beveling can be seen but the foundation of the wall lies below the level of the present hill.

The Parian Chronicle^[5] mentions that the Athenians expelled the Peisistratids from the "Pelasgikon teichos". Herodotus^[6] relates that before the expulsion of the Pelasgians from Attica, the land under Hymettus had been given to them as a dwelling-place in reward for the wall that had once been built around the Acropolis.

Said to have been built by the Pelasgians, there are some remains of this wall still evident in modern Athens. The wall was believed to be 6 m (20 ft) thick according to archaeological remains of the site.^[7]

• Sketch of the course of the Pelasgic wall.
• Pelasgic wall on the summit of the Acropolis, south of the Modern Museum
• Southwest wing of the Propylaea and Pelasgic wall.