Mouassine is the prime zone. It sits in the northwestern corner of the medina, roughly ten minutes on foot from Djemaa el-Fna but a world apart in atmosphere. The lanes here are narrow enough that donkeys still make deliveries, and the density of 17th-to-19th-century buildings is the highest in the city. The Mouassine Mosque and the nearby Spice Square (Rahba Kedima) anchor the quarter. Riad Kniza and Dar Darma are both here.
Bab Doukkala to the northwest has slightly wider streets and fewer tourists, which means you can work a courtyard shot in the morning without someone walking into your frame. The architecture is less concentrated with grand examples but the street-level details — doorways, lanterns, hand-painted shop signs — are excellent for contextual travel photography.
The Mellah (Jewish quarter, southeast near the Royal Palace) offers a visually distinct character: French Protectorate-era wrought-iron balconies, Star of David motifs on doors, and a more melancholy quiet that suits black-and-white or muted-palette work. Very few riads here have been renovated for tourism, which is either a drawback or an asset depending on your priorities.
Avoid the blocks immediately adjacent to Djemaa el-Fna if architectural authenticity is your goal. Heavy tourist pressure over the past two decades has meant that many original structures have been gut-renovated with mass-produced tile, concrete columns, and Instagram-optimised paint jobs that have no historical basis. They photograph well but tell a false story about the city.