The municipal authorities in the upper town extended the east side of the priory building between 1600 and 1700. Further alterations were carried out by the architect Giovambattista Vassalli between 1777 and 1781. The priory building was then demolished in 1867 and replaced with the new municipal headquarters, designed by the engineer Guglielmo Prosperi from Macerata and built by the Basile brothers from Porto San Giorgio. The building has three floors, overlooking the square. On the ground floor there is an arcade, at the centre of which is the entrance. The lobby displays a Roman plaque with the inscription ‘Cluentensis Vicus’, the ancient name of the city. A large staircase leads up to the next floor, where there are the municipal offices and council chamber, which are decorated with frescoes depicting the stories of the Aeneid, painted in honour of Annibal Caro by the famous local artist Ulisse Ribustini at the end of the 19th century, and portraits of local aristocrats. The top floor houses a collection of 19th-century arms and war remnants from the 16th and 17th centuries.