According to the view which has long held the field and is still the most widely accepted, the Long Walls which the Athenians constructed in the fifth century to connect their town and harbour were three in number, viz., two outer walls extending respectively to the northern and southern sections of the harbour fortifications, and an intermediate wall running longitudinally in the gap between the outer pair.
This theory rests on evidence which prima facie appears very strong. Harpocration distinctly enumerates three walls, known respectively as the Northern, the Southern or Middle, and the Phaleric one, and in support of his statement he quotes a passage from Aristophanes, in which three walls are likewise mentioned. The same number of walls also seems to be implied in a passage of Thucydides, where mention is made, firstly, of a Phaleric wall, and secondly, of ‘Long Walls,’ which should presumably be identified with the Northern and Southern walls of Harpocration, so as to make three walls in all.