Its opening celebrations were held in 1661 after Antonio Raggi had completed the decorations in stucco inside the dome.
The religious building, open to the public, has a Greek cross layout surmounted by a dome coated with layers of lead and with a lantern to illuminate the interior. The façade is developed vertically and structured on two levels: the portal is in the lower part while in the upper part you see a large window and a tympanum bearing the Chigi family’s crest.
Inside the church are paintings by Borgognone and works by Pietro da Cortona: an alterpiece in the main alter illustrating La Crocifissione con Maria (The Crucifixion with Mary); La Maddalena and San Giovanni (Magdalena and St. John). as well as the stuccoworks by Antonio Raggi.
The Church of St. Thomas from Villanova
The Collegiata Parrocchiale Pontificia (Collegiate Church of St. Thomas of Villanova) that stands in the town's main square was built as of 1658 and commissioned by Pope Alexander VII Chigi: the project was entrusted to the mastermind of Gian Lorenzo Bernini.