One of the biggest mosques in Marrakech was built in the 12th century. Unfortunately, non-Muslims aren’t allowed to enter the mosque, but the exterior is also very nice. Notice especially the minaret of this mosque - it is decorated with three gilded spheres as well as with tile mosaics.
Closed to non-Muslims.
Wikipedia https://en.wikipedia.org/wiki/Kasbah_Mosque,_Marrakesh
Address Rue Boutouille, Méchouar Kasba 40000, Morocco
Coordinates 31°37'3.391" N -7°59'19.95" E