When the Arabs took Crete in 824, they laid out a major town on the site of the small Byzantine settlement.
According to Leo the Deacon (10th century), the Arab fortress was protected on one side by the sea and on the others by a mighty wall lying on a stone base founded on the rock below. He further claims that the wall was built of bricks made of earth mixed with goat and pig hair, and was broad enough to allow two chariots to pass.
Consisting of curtain walls and towers, the fortress was surrounded by two wide, deep ditches or moats, giving rise to the Arab name Rabdh el Khandak - "The Fortress of the Moat", which may in turn be the origin of the Greek name Chandax.
"A wall of compressed earth and hair, broad enough to allow two chariots to pass and of no small height, was founded on a level stone base crowned with a cornice. Two broad, deep ditches surrounded this. Breaching by battering rams was effected at a point in the base consisting of sandstone. Once the compressed wall had been dug under in this manner and wooden props had been burnt, two towers together with the construction between them were demolished."