The second largest mosque in the world was partly built on the water; its minaret tops out at 200m above the sea. The prayer hall, perfectly symmetrical, is supported by 78 pillars covered with a glinting patchwork of granite and marble; the roofing is covered with emerald green tiles. The mosque can hold 25 000 worshippers (80 000 on the esplanade). The complex, superbly decorated by craftsmen from all over Morocco, it is a masterpiece. Don't hesitate to visit the museum and Médiathèque (media library).