Montecastrilli origin has to be found during the Annibal life, which passed by here and camped on the "Castrillorum", which in latin means "camping".
Before belonging to the papal state, the town was under the power of Todi, and its history was characterised by the fights between the nobles families of Todi all over the 400's. Of the original town, today remain the walls with towers, on which the two doors Porta Amerina and Porta Medioevale open. It became an independent commun in 1975, and today it includes the small villages of Castel dell'Aquila, Castel Todino, Farnetta, Quadrelli and Collesecco.The convent of clarisse dating 1400 should be definetly visited; in the parish church of interest is a wood cross of the XV century; nearby San Lorenzo in Nifili of the XI century, is a remarkable example of the umbrian romanic stye.
Recently two marvelous paintings coming from the monaster of Montecastrilli have been restored showing San Nicola from Bari and San Bonaventura from Bagnoreggio. Both the paintings, of unknown author, have been done during the first half of 1700. They can be admired in the church of Santa Chiara.