The ruins at El Badi Palace are absolutely unreal. We ended up sitting there for quite a while just taking in how massive everything was and imagining what it must've looked like hundreds of years ago. When we visited, the gardens were under construction and they were renovating the main building overlooking the large reflecting pool, so I know we didn't get to see it at its best. Even so, it was still one of the coolest places we visited in Marrakech and somewhere I'd definitely recommend adding to your itinerary.