Il Filarete, The Martyrdom of St. Peter: Detail, the mausolea
The two pyramids and the building shown in the center once lined the street that led to St. Peter's. The figure sitting by the pyramid on the left is the personification of Rome – compare this image of Roma on a coin of 247 AD:
(The small figure on Roma's hand in the coin and the bronze is Nike.)
View the whole image of the martyrdom.
Detail of the Martyrdom: Photographed at the site by Richard Stracke, shared under Attribution-NonCommercial-ShareAlike license.
Coin: Posted by Johny Sysel on Wikimedia Commons