Fortezza, i.e. the fortress on Paleokastro hill, on the north coast of Rethymno, was built in the second half of the 16th century.

Specifically, its construction began in 1573, two years after the pirate Ulutz Ali looted and burned the town. The fortress was built according to the principles of the bastion system. Inside the fortress there are buildings from the Venetian, Ottoman and modern periods. Excavations have revealed residential remains from the Hellenistic period.