Heri es-Souani was Moulay Ismail's granaries, quite giganting in their scale. The granaries stored grain and hay to feed the 12,000 royal horses.
The granaries have massive walls and tiny windows, effectively creating cool storage conditions.
Restorations are ongoing, and enough has been reconstructred to allow it to be used as a film location. Perhaps the most famous is the The Last Temptation of Christ from 1988, by Martin Scorcese.
Admission is 10dh, open all days, 9.00-12.00 and 15-18.30.