houara Tannery is built in the 11th century and is the largest tannery in the city. It is located in the Fes el Bali, the oldest medina quarter of the city, near the Saffarin Madrasa along the river. Since the inception of the city, tanning industry has been continually operating in the same fashion as it did in the early centuries. Today, the tanning industry in the city is considered one of the main tourist attractions.
The most notable feature of the tannery is the numerous stone vessels filled with the different colors of dyes or white liquids. Hides of cows, sheep, goats and camels are processed here by soaking into the vessels. At first, they are soaked into the white liquids made of cow urine, pigeon feces, quicklime, salt and water, in order to break down the tough leather. This process takes two to three days, making the leather malleable for absorbing the dye. The hides are then soaked into the dyeing water made of natural vegetables such as poppy for red, indigo for blue and henna for orange. After the dyeing, they are dried under the sun. The hides produce the high quality leather goods such as bags, coats, shoes and slippers. The production process consists of manual labor and involves no modern machinery, and has been retained its method since the medieval era.(Wikipedia)