There's something unnerving yet gripping about exploring vaults and crypts. If this seems interesting to you, stop by Moulay Idriss Zawiya.
This tomb site in Fes El Bali comes recommended by travelers, so make sure it features on your must-see list. Don't stop there, though. There are a lot more spots waiting for you to experience after Moulay Idriss Zawiya. University of Al Quaraouiyine, Medersa Bou-Inania, and Marinid Tombs are not far away.