The church dates from the thirteenth century and has an adjoining convent. It was originally dedicated to St. Anthony and belonged to the Antonian order. In the fourteenth century it passed to the Order of Saint Augustine, who became the patron of the city, and it was dedicated to him. After being bandoned during the Napoleonic era, it was restored by Pope Leo XIII.
In the main portal you can admire two lions in Cistercian style gripping sheep and hares with claws, supported by columns. A second Gothic portal on the right side of the church comes from the abbey of Valvisciolo, destroyed in the fourteenth century.
Inside, in the form of a Latin cross with a single nave, you can admire a wooden truss, with a triumphal arch, an altarpiece of Saint Augustine, the work of Tito Troja. He was also artist of the paintings on the vault representing the liberality of Pope Leo XIII, surrounded by the papal court and the triumph of the Augustinian Order. Beside the altar there is a magnificent Swiss organ, a gift from the Diocese of San Gallo to Pope Leo XIII.