In Riviera street we can still see the remains of a structure probably built around the 12 th century, composed of a tower, a mansion and a fortified enclosure. It is regarded as the place where, at the end of the 13 th century the place between Guelphs and Ghibellines was signed.
Only few strips of the defensive wall are kept in which we can see squared stones courses and parts of the openings regarding the original masonry. 
The tower walls kept till to a height of about 9 metres. It has a square base formed by big square ashlars; it shows traces of a collapse who cut obliquely a side, as per Federici Tower. We can presume that the two buildings had a similar destiny for unknown events.
Original openings are not present in the tower wall; they presume that the entry was from the first floor, using wood stairs.
There are various similitudes with the defensive enclosure, and so the buildings are contemporaneous.
Also the mansion, like the tower, suffered several modification in the course of centuries and only to think back over the events.