The Sant'Agata church stands on the highest part of Prossedi and dominates the town. Its construction began in 1655 and expanded in the late 1700s but work was interrupted several times due to lack of funds. The church was completed in 1829 and dedicated to St. Agatha, virgin and martyr. Of neoclassical style, it has a plan of a Greek cross with apses and chapels in the corners of the cross. The sacristy belongs almost certainly to the early construction as in fact does the plan of the church with a central dome. In the sacristy there is a beautiful carved wooden confessional from the seventeenth century Roman school. Behind the altar there is a majestic wooden choir with 13 finely decorated places. On a wooden loft in the doorway is located a large pipe organ from 1861, the work of the organ builder Peter Pantanella.