It is an example of a medieval "Mansio" (residence) that belonged to the Knights Templar. The castle includes the ancient church and the “spedale” (hotel) for the pilgrims in transit to Rome
on the Via Francigena. The complex is near the ancient crossing of the Via Francigena over the Staggia River, near the Bonizio bridge, now destroyed.
The castle dates from the 11th century. On 5 September 1140, it was donated by Gottifredo di Arnolfo and Arnolfino di Cristofano, heirs of the founders, to the Monks of the Saint Michael Abbey in Poggio Marturi. The monks entrusted it to the Knights of the Temple, becoming one of the numerous "Mansiones" or "Domus Templi" on the Via Francigena.
Seen from above, the complex assumes a nearly trapezoidal shape, in that it follows, on the west side, the course of the River Staggia. In the courtyard, visitors will see the premises of the convent for the Knights, the small guest-rooms and the flight of steps for access to the upper floor.
The Magistral Church of San Giovanni in Jerusalem is designed in a pure Romanesque style, as it can be seen from the altar. The restoration has shown the Burgundian-Cistercian influence of the vault construction.