The Castello di Arechi is a medieval castle , located at a height of about 300 meters above sea level, overlooking the city and the Gulf of Salerno . It is said of Arechi because the construction of this fortification is traditionally associated with the Lombard duke Arechi II .

In the museum of the castle are exhibited finds from the excavations carried out on the site: these are ceramics, glass, metal objects and coins. This museum is equipped with speakers and screens, which illustrate the geography of the castle and give historical notions of that, giving a logical and cultural sense to the visitor.