(_Porta del Popolo._)
_Passing through the Porta del Popolo_, built in 1561 by Vignola, a
short walk under the walls, to the right, brings us to the Muro Torto,
a piece of masonry of the time of Sylla, and held to be under the
special protection of S. Peter (Procopius, "B. G." i. 13).