Aposa river still enters the city here, on the corner of via Rubbiani. In the building, that is part of the old walls surrounding the center, there were the devices of the grading placed at the entrance. Aposa and the moat were built on two different levels. Another similar building was used to let the channel of Savena cross the river. The description is taken from "Il Torrente Aposa" a cura di Marco Poli