The defensive structures also include four excellently-preserved dams in the largest ravines. The dams are between 1.5–2.3 m (4 ft 11 in–7 ft 7 in) thick, and up to 5 m (16 ft) high. That they are dams and not walls is proven by their position, as well as their construction: on the uphill side, they are covered by a layer of mortar whose density indicates it was a water barrier.