The fort Kales was built by the Venetians in the 13th century AD, to protect the town of Ierapetra from its enemies. In 1508 it was destroyed by an earthquake and the Turkish raids. The damage was not repaired, perhaps because it was very serious and there was no funding.
When the town of Ierapetra was occupied by the Turks in 1647, the castle was repaired and used for the defense of the town. The name Kales comes from this period, since it comes from the Turkish word "kule", which means tower.
All these years Kales dominates the entrance to the old harbor of Ierapetra, witnessing the history of the city. Today you can visit the castle and watch the cultural events organized by the local municipality.