The obelisk, now at the centre of the Piazza Navona, cannot have been there in ancient times as it was once believed. Remains of the cauea can be seen under a modern construction on the curved side. The remains of the straight side are preserved under St Agnes.
Christian hagiography locates the brothel where the saint was martyred near the Stadium.
The fa ade was about 275 m long by 106 m wide. The outer line of the fa ade was made of arches lying on piles of travertine with Ionic columns. Between the first and the second gallery, there was a part made of pillars and radial walls in which there were staircases. From there, travertine was replaced by brick. Between the second and the third gallery there were large rooms supported by pillars and other staircases.