Osimo’s town walls are one of the most important evidence of town planning made by the ancient Roman colony of Auximum, founded in the 2^nd century A.D. and located between the Musone and Aspio Valleys. The town walls were built by the aristocracy; the historian Livio reported that the censors Q. Fulvius Flaccus and A. Postumius Albinus to build this project. The town walls are well preserved, in particular under the Saint Francis Convent. The walls are made of tuff, cut into big rectangular stones using the opus quadratum techinque. The town walls were three: Porta Vetus Auximum, on the way to Ancona, Porta Musone on the way to Cingulum, Aesis and Trea and Porta Potentia, no longer visible today. 
Near the centre of Osimo, there is the Fonte Magna, named after Pompeo Magno, who was in this area during the civil war against Caesar, even if the name is mostly explained by the fact that the Fonte Magna was one of the main source of water supply of Osimo. The structure has an important role in the archaeological scenario of the Marche Region, since it is one of the few monuments cited by historical sources. The Fonte Magna was mentioned by Procopius of Caesarea in his The Gothic War, because it was a strategic point for the commander of the Byzantine Empire Belisario who wanted to conquer the town occupied by the Goths.