The short answer
The medina's rooftops look over the Koutoubia, the spice square and, on clear days, the Atlas. Café des Épices above the spice square, Cafe Medina Rouge opposite the Koutoubia, Le Grand Bazar on Jemaa el-Fnaa, and Kasbah Café facing the Saadian Tombs are all well-known rooftop tables. Go at sunset.
In more detail
Café des Épices is widely credited as the first rooftop café in Marrakech, looking over Rahba Kedima, the spice square, with views to the Atlas. Nearby, Atay Cafe is a lantern-covered tea house with a high terrace over the Ben Youssef Mosque. Ayaso Medina, a vegetarian and vegan café on the same square, has a rooftop popular at sunset.
For the Koutoubia, Cafe Medina Rouge on Rue Koutoubia serves couscous, tagines and pastilla with a direct view of the minaret. Le Grand Bazar, a century-old hotel turned restaurant on Jemaa el-Fnaa, has a rooftop terrace of about 600 square metres facing the minaret. Dardar Rooftop, south of the square, adds sunset DJ sets and views towards the Atlas.
In the south of the medina, Kasbah Café climbs three floors to an open roof facing the Saadian Tombs and the Kasbah Mosque, and Le Tanjia in the Mellah looks over the Badii and Bahia palaces. Outside the walls, Le Douar sits on the roof of the Meydene cultural centre at M Avenue in Hivernage.
Rooftops fill at sunset, so arrive early or book ahead. In winter the terraces cool fast once the sun goes, so bring a layer.