The ground plan follows the Counter-Reformation design of churches established at the "Gesù"; a single main nave with transepts and side chapels, leading towards the High Altar. Neri had intended that the interior be plain with whitewashed walls but it was filled by patrons with various artistic works, mainly during the period from 1620 to 1690, including masterworks by some of the principal artists of those decades in Rome. It is renowned for its altarpieces by Barocci, Pietro da Cortona's ceilings, and the Rubens slate and copper altarpiece.