The Romanesque style monastery, was founded by Pope Celestine V, and it held his remains up to 1327 and became a pilgrimage site. The church was ruled by the Order of the Celestini until the seventeenth century when, for a shortage of monks, it was attached to Saint Eusebius in Rome. The exterior comprises a façade with lintel doorway crowned with a simple bezel setting, a circular window and simple bell tower. The poor architectural character is obvious as is the Cistercian style recovery. At the centre of the monastery there is a cloister, around which are arranged the rooms of the monks. In Ferentino Celestine V heart still remains, kept in the monastery of the Poor Clarisse and in honour of the saint, the patron of the city, every year the traditional Palio or ring joust is celebrated.