A rare example of a fortified monastery, this Castle was home to the Benedictine Monastery of St. Peter until 1572, the year of the beginning of its decline as a defensive structure.

The first mention of the Castle dates back to the end of the twelfth century and its structure, similar to that of a ricetto (fortified refuge), surrounded not only the monastery but also part of the village. The relationship between the population of Lenta and the nuns was not always the best and was marked by disputes.

The Castle still features an imposing appearance that reminds of its original role as a center of defense and power. Evidence of the latter is offered by the many frescoes that still exist, even if in poor conditions.