The fort of Koules is located in Paleokastro area, 12km east of Chania, near the village of Kalami and close to the ruins of ancient Aptera. The fort was built by the Turks after the Cretan Revolution of 1866, in the framework of a program to control Crete from a network of towers. The fortress was constructed by Hussein Avni Pasha, the Turkish governor of Crete and is a representative sample of the forting architecture of the 19th century.
The fort was built to control the valley of Vamos, which was amid the passage to Chania. Together with the other towers built by the Turks in Vamos, it controlled the gulf of Souda and supported the nearby fort Intzedin.
Koules of Aptera or Soumpasis fort, as otherwise called, 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 communicated with the fortress Intzedin and the towers of Kalives and Nio Chorio.
The fort was the largest fortification work of its era 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 climbed on the ramparts, which were on the roof of Koules, through internal wooden stairs. The fort had 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 Horafia.
Apart from the towers of Aptera and Nio Chorio, the Turks have built several other rows of towers because of the strategic position of Apokoronas. All of them had direct sight to Aptera Koules and their number exceeded 20 (almost every village had 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 series included the Koules of Achatzikia, Vafes, Tsouristra, Kimina, Embrosnero, 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 of Chalase, Vamos, Kastellia of Souri, Ganades, Selia and Kaina. They all had excellent cooperation, thus any move around would be perceived.