The fort Koules is located in Paleokastro area, 12km east of Chania, near the village Megala Chorafia and close to the ruins of ancient Aptera. The fort was built by the Ottomans after the Cretan Revolution of 1866, during of a large scale program to control Crete through a network of defensive towers, called koules. The fortress was constructed by Hussein Avni Pasha, the Turkish governor of Crete, and is a representative sample of the defensive architecture of the 19th century.
The fort was built to control the valley of Apokoronas, which was the main passage to Chania area from the central part of Crete. Moreover, in collaboration with several towers built by the Turks in the area of Apokoronas, it controlled the bay of Souda and supported the nearby fort Intzedin.
Koules of Aptera, also known as fort Soumbasis, still survives today in very good condition. It was equipped with two towers, one with west orientation (controlled the passage to Keramia area) and the other to the east (looking to Kalives). The first communicated with the fortress of Souda islet, while the second had visual contact with the fortress Intzedin and the forts of Kalives and Nio Chorio.
The fort was the largest fortification work of its era in Crete and included areas which were developed on a symmetrical shape Π, around a rectangular courtyard. The circular towers occupied the southwest and southeast corners of the fort, while the main gate was located on the east side, protected by a suitable recess (ears).
The soldiers could reach the ramparts, which were on the roof the koule, through internal wooden stairs. The fort was equipped with all the necessary facilities for quartering, accommodating officers, storage, imprisonment, food catering, etc. The current good condition of the fort is due to the excellent workmanship of its walls. After the Turks left Crete, Aptera Koules was used as a school for the village of Megala Chorafia.
Apart from the towers of Aptera and Nio Chorio, the Turks have built several other rows of towers because of the strategic position of the province Apokoronas. All of them had direct sight to Aptera Koules and their number exceeded 20 (almost every village hosted one). One such series of koules was composed by the towers of Kares, Melidoni (there are remains today) and two more in Ramni village. A second row of towers included the koules of Achatzikias, Vafes, Tsouristra, Kimina, Embrosneros, Chalase, Alikambos and Krapi. Other towers have been found in Gavalani, near Georgioupolis, and Tsigounas, near Kournas. Finally, another series of Koules were built on the eastern slopes of the valley; Kefalades at Chalase, Vamos, Kastellia at Souri, Ganades, Selia and Kaina. They all had excellent cooperation, thus any move around would be perceived.