Considered by many visitors to be the main attraction of the city of Salerno, the Arechi Castle represents the history of the city of Salerno, as well as the place from which to admire a breathtaking view of the entire Gulf of Salerno.

Salerno's Arechi Castle is a medieval castle, located at a height of about 300 meters above sea level on Mount Bonadies, overlooking the entire city and the Gulf of Salerno.
The castle owes its name to the Lombard prince Arechi II, who transferred the duchy from Benevento to Salerno and decided to use the existing fortress as his new home.
According to some archaeological investigations, the earliest construction phase of the castle, dates back to the 6th century by Gothic-Byzantine craftsmen of the Narsete period. Other scholars, however, have stated that the first fort on Bonadies Hill was built in the 3rd century, in the late Roman period.
Later in the eighth century, when the city of Salerno represented a bridgehead for maritime trade in the Mediterranean, the Arechi castle assumed great military importance with the Lombard prince Arechi II, in fact the prince in order to make it impregnable decided to make some changes not only architecturally but also functionally, in fact Prince Arechi II ordered both the construction of higher defensive walls, as well as the construction of watchtowers along the perimeter of the castle, joined together by a crenellated wall and drawbridges. On the northwest still stands the watchtower called the "Bastille" which highlights the validity of the castle's defensive system, which made it an impregnable fort for many years.

In 1077 the "Castle of Arechi" was robbed from Gisulph II, the last Lombard prince of Salerno, to become a Norman stronghold. Finally, the Arechi castle lost importance during the Aragonese period, only to be completely abandoned in the 19th century.

After a long period of neglect and becoming in the possession of a family of local factors, following the Unification of Italy, the castle became, at the behest of President Girolamo Bottiglieri, the property of the Province of Salerno, which began restoration work. In 2001, the nearby Bastille was reopened. On March 1, 1992, Poste Italiane dedicated a postage stamp to the blockhouse.

The monumental complex of the Arechi Castle houses a medieval museum, in which it is possible to find ancient weapons, pottery, glass and coins, that is, all the objects found on site. In addition, Arechi Castle offers a magnificent view of the Gulf of Salerno and the entire city, and is surrounded by numerous nature trails through the Mediterranean maquis. Finally, nowadays Arechi Castle represents a perfect location for celebrating events and weddings, also thanks to the breathtaking view from the restaurant set up inside the structure.