The relation of the successive walls and terraces is shown by the ground-plan in Fig. 9[23]. The double shaded lines from A to E and D show the irregular course of the old Pelasgic wall. The dotted lines from B to F show the polygonal supporting wall of the first terrace. It ran, as is seen, nearly parallel to the Parthenon. Its course is lost to sight after it passes under the new museum, but originally it certainly joined the Pelasgic wall at C. At B was the stairway joining the two terraces. Next came the time when, as the rubble fell over the wall, larger space was needed, and a portion of the Pelasgic wall was utilized and raised. This is shown by the thick black line from B to E coincident with the Pelasgic wall; the masonry here was of quadrangular poros blocks. The coincidence with the Pelasgic wall was only partial. At GH there jutted out an independent angular outpost, and again at EF the new wall is separate from the old; at FD it coincided with the earlier polygonal terrace wall. Kimon’s wall is indicated by the outside double lines, and in the space between these lines and the wall HEK lay the _débris_ of the Persian War. Above that _débris_ lay a still later stratum, deposited during the building operations of Perikles. [Illustration: FIG. 9.] The various terraces and walls have been examined somewhat in detail, because their examination helps us to realize as nothing else could how artificial a structure is the south side of the Acropolis, and also—a point, to us, of paramount importance—how different was the early condition of the hill from its later appearance. Before we pass to the consideration of the second clause in the historian’s statement, ‘_together with what is below it towards about south_,’ it is necessary to say a word as to when the old fortress walls were built and by whom. Kimon and Themistocles we know, but who were these earlier master-builders? A red-figured vase painter of the fifth century B.C. gives us what would have seemed to a contemporary Athenian a safe and satisfactory answer—‘There were giants in those days.’ The design in Fig. 10 is from a skyphos[24] in the Louvre Museum. Athena is about to fortify her chosen hill. She wears no aegis, for her work is peaceful; she has planted her spear in the ground perhaps as a measuring rod, and she has chosen her workman. A great giant, his name _Gigas_, inscribed over him, toils after her, bearing a huge ‘Cyclopean’ rock. She points with her hand where he is to lay it. [Illustration: FIG. 10.]