The main tower of the castle of Aliforni still retains the characteristic summit corbels that supported the crenellated platform. The walls, built with large blocks of sandstone, followed the elliptical shape of the surrounding hill for a length of about 240 metres. The track-breaking towers reinforced the wall structure and allowed for the placement of heavy armaments. The castle was surrounded by a moat crossed by a drawbridge, while the entrance was through a fortified door facing south.
The main tower, recently restored, is well preserved and develops vertically over seven floors. Inside the tower there are numerous loopholes for sighting and using weapons. An engraving on white limestone, located in the south wall of the tower near the entrance, appears to represent the coat of arms of the Franchi family, probably associated with Don Liberato di Sensino Franchi Bertelli, a noble prelate of San Severino with a great interest in the art.