Located 16km south of Rethymnon, near the Monopari settlement in Varsamonero, is a steep and isolated hill known as Kastellos, surrounded by a torrent. In 1206, Genoese pirate Enrico Pescatore established one of the 15 Genoese forts on this hill, naming it Bonriparo (meaning strong fort). The village of Monopari derives its name from this fort. Alternatively, some believe the fortress was constructed during the second Byzantine Period (1185) and was called the Tower of Melissinos.

Monopari was safeguarded by a lengthy double wall on its western side, while cliffs physically fortified the other sides. The Venetians later utilized the fort, adding some buildings that still stand today.

The so-called “Two Syvritos” revolution took place in Monopari, involving the two mountainous provinces of Rethymnon prefecture: Amari (Upper Syvritos) and Agios Vasilios (Lower Syvritos). This revolt was also known as the Skordilis and Melissinos rebellion. Peter Filikanevos, the Venetian castellan of Bonriparo, once stole horses and sheep from the Skordilis family. When Ioannis Skordilis complained to Venetian duke Pablo Kourino, he failed to resolve the issue fairly, igniting a significant revolution in the two Rethymnon provinces. The revolution lasted from 1217 to 1236, ending when the Venetians agreed to grant feuds, equal rights, and privileges to the Skordilis and Melissinos families.