The church of Sant'Ignazio di Loyola was built on a design by the Jesuit mathematician Orazio Grassi, based on the plans of Carlo Maderno and others, and at the expense of Cardinal Ludovico Ludovisi, nephew of Gregorio XV, as the inscription on the facade recalls; this is inspired by that of the nearby church of Gesù, with two orders of pilasters and Corinthian columns, enriched by large windows, niches with tympanum and folders.