Poggioprimocaso consists of three distinct parts: Colle Curioso, Spinacresce e Pie della Villa.

The latter, as its name suggests, is the continuation lower down the hill of the central part, stretching down the hill slope that falls to the gully of Fosso di Paterno. The central part (Spinacresce) consists nowadays of scattered houses that were originally behind walls that can still be seen in the lower part, where there is also a formerly imposing tower now in ruins.  Finally, Colle Curioso is a group of houses with the ground floor used for the cattle.

This type of village consisting of a central nucleus, obviously the castle with its stronghold, of the lower part, the village that grew along the road to Giappiedi and of the higher part was not customary and appears to have been deliberately organised.