Christianization accounts for the survival of the cella and portico of the temple through the centuries, though it did not preserve the edifice from all damage. Originally, the podium was faced with white marble slabs, with matching marble mouldings at the top and bottom. Most of the marble facing was scavenged, except for the moulding. The deep grooves in the temple's columns are supposed to date to a medieval attempt to dismantle the pillared portico, either for spolia or to destroy the pagan temple. The grooves also may have been used to attach a makeshift roof over the portico. Also in the Middle Ages, a staircase was built on the side facing the Forum, but it is now impossible to enter from that side because there is a gap of circa between the foot of the steps and the bronze door. Before the archeological excavations, the ground level was at this door. Excavations in front of the temple were undertaken in 1546, again in 1810, and at intervals from 1876.