The Alhambra's Little Brother
The Bahia Palace, in my opinion, is the most spectacular official monument to see in Marrakesh, even ahead of the Ben Youssef Madrasa. I'm not much of a history buff to be honest, so I can't tell you much on that end, but I can tell you that the French colonists found it so spectacular that they booted out the previous owner and installed their local offices there during that time. Nowadays though, it's a museum and one well worth visiting, especially when the entry fee is little more than a dollar.
The highlight here are the intricate wood engravings on the ceilings, many of which border on mind-blowing in terms of ornateness. The austere palace courtyard was another highlight. Apparently, it was once used to hold prisoners begging for forgiveness. The emir would make them wait in the hot sun for hours on end in the patio to beg clemency. It's a really beautiful place and at the top of my list during my visit to Marrakech.