Considered a 'unicum' of the Lecce Baroque, it's one of the most important and admired churches in Lecce. Construction began in 1549 at the request of the Celestine fathers, after the demolition of the ancient temple and monastery founded in the second half of the 1300s, at the behest of Gualtiero VI of Brienne, Count of Lecce. Built starting in 1549 and completed in 1699, important Lecce architects of the time took turns, such as: Gabriele Riccardi, Francesco Antonio Zimbalo and Cesare Penna with the help of master stonemasons and carvers from the Lecce area. The allegorical façade divided into three orders and the adjoining rose window is of considerable splendor. Inside, worthy of note, we find the eighteenth-century high altar, the coffered ceiling in gilded wood that encloses the canvas of the "Holy Trinity", the side aisles that house 17 chapels where altars and columns in Baroque style are richly decorated.