Construction of the Shrine of Santa Filomena or Church of Saint Mary of Graces Grazie was begun in 1617 and completed around 1630 thanks to funds collected from the cutting of the Vallicelle woods.

The church was built in the shape of a Latin cross with a nave, an elegant dome, in the Renaissance style, and an altar adorned with precious and rare marble. On the eastern side was a 50-meter-high bell tower that had a dome on top with a bronze ball surmounted by a flag and a cross. On May 30, 1673, the tower was struck by lightning and collapsed, damaging the church. It was faithfully rebuilt with the support of the people. Two bell towers were inserted in the mid-eighteenth century.

The facade is covered with yellow stucco and flanked by two towers: one for the clock, the other for the bell tower. The architecture is neoclassical with Ionic and Corinthian capitals.

 The church of Santa Maria delle Grazie in the early 1800s became the Shrine of Santa Filomena. The body of the saint, found in Rome on May 25, 1802, was brought to Mugnano by priest Don Francesco De Lucia on August 10, 1805. Fr. Francesco De Lucia was the first rector of the shrine, who founded and extended the devotion of St. Philomena in the Kingdom of the Two Sicilies and overseas to the Americas.

 Great personalities have visited the shrine with rich gifts: Cardinal Ruffo-Cilla of Naples, Leo XII, Pope Gregory XVI, Pius IX who went on pilgrimage accompanied by King Ferdinand II on Nov. 7, 1849, Pauline Jaricott (founder of the Pontifical Missionary Works) who was miraculously blessed by St. Philomena in Mugnano on Aug. 10, 1835, the Holy Curé d'Ars, Maria Cristina of Savoy, wife of Ferdinand II of Bourbon, Leo XIII.

 Popes devoted to and promoters of the cult of St. Philomena included Leo XII and Leo XVI after the miracle of Pauline Jaricott, which occurred before the altar of St. Philomena on August 10, 1835, making the cult of the saint official throughout the church; Leo XIII promulgator of the Archconfraternity Universal of St. Philomena, St. Pius X, a great devotee who enriched the shrine with valuable gifts.