Around 1000 the monks allied themselves with various noble families to colonize new lands, to have a control over the people and to defend against incursions of the barbarians. Even in Roccasecca, the castle was founded in 994 by order of the abbot of Montecassino, allied with the D'Aquino family of Pontecorvo, and built above the fortress on Mount Asprano. According to a legend St. Thomas Aquinas was born in this castle in the thirteenth century. The castle lost commercial control of the valley in the seventeenth century, and quickly declined. A cylindrical tower is still standing, while the rectangular structure is the thirteenth-century model, and is kept in good condition.