Parker, John Henry: The archaeology of Rome (1,2): Illustrations to I. The primitive fortifications. II. The walls and gates of Rome. III. The historical constructions of walls (Oxford [u.a.], 1874)

Primitive Fortifications—Plans and Diagrams.

Plate I.
General Plan of Rome, with the Walls of the Kings, of Aure-
lian, and of the Popes.
In this small Plan the hills are tinted grey, and the valleys left
white, with the streams of water flowing through them, green; the
Walls of the Kings are tinted red; that of Aurelian, with the towers,
is solid black; that of the Leonine City and the Hadrianum, a thick
black line ; and that of the Popes in black outline.
This plan, with the section above, was taken originally from what
was considered as the best geological plan of Rome. But it does
not profess to be a geological plan in its present form, it is only
intended to give a general idea of the nature of the ground on
which the City of Rome stands, in the valley of the Tiber. The
Seven Hills have probably all been originally promontories, from
the high table-land on each side. The three Colles, the Quirinal,
Viminal, and Esquiline, clearly are so, and the Janiculum and
Vatican on the western side.