Mighty construction in alberese stone of the XIV century [1, 2], was built by Earls Guidi di Poppi in place of a Longobard sighting tower. Then, the building belonged to the Pazzi family and to Castellani, taking from the last ones the name that identifies it still today.
It was a part, together with the castle of Incisa and the Tower Bandinella, of an important defending line on ward of the viability of the place. The building underwent many readjustments in time, but of the late-medieval period, remains the quadrilateral form with the low angular tower and the bastioned basement and the cellars. An internal yard, with arches held by octagonal columns, leads to the three upper floors and to cellars. From the beginning of the 20th century, it belongs to family Pegna, whom is due the restoration assigned in 1938 to architect Guido Morozzi of the Monuments Department.