16km south of Rethymno, near the settlement of Monopari in Varsamonero, there is a steep and isolated hill, encircled by the local torrent. The hill is called Kastellos and, atop of it, the Genoese pirate Henry Pescatore founded one of the 15 forts built by the Genoese all over Crete in 1206. The fort was named Bonriparo (meaning strong fort), after which the village Monopari is named.
According to another version, the fortress was built during the second Byzantine Period (1185) and was known as the Tower of Melissinos. Monopari was protected by a double long wall on its west side and the other sides were physically rugged. Later the fort was used by the Venetians, who added some buildings that have survived till today.
In Monopari took place the so-called revolution of "Two Syvritos", i.e. the two mountainous provinces of Rethymnon, Amari (Upper Syvritos) and St. Basil (Lower Syvritos). The revolt was also known as the revolt of Skordilis and Melissinos. The Venetian castellano of Bonriparo, Peter Filikanevos, once stole the horses and the sheep belonging to the family of Skordilis. John Skordilis complained to the Venetian duke Paul Kourino, who did not resolve the matter fairly. Thus, a great revolution broke out in the two provinces of Rethymnon. The revolution lasted from 1217 until 1236, when the Venetians agreed to offer feuds, equal rights and privileges to the families of Skordilis and Melissenos.