The vibrant colours & smells of Djemaa el Fna at sunset.
Shopping & bargaining in the medina.
Taking a tour of the back streets & old palaces.
Staying in beautifully restored old riads.
Eating at fantastic restaurants.
Visiting the surrounding gardens.
Quick Tips:
I'd strongly recommend taking at least one guided tour around the back streets of Marrakesh - it's impossible (& maybe not safe) to get right into the heart of the 'local' medina without a guide & it's well worth it.
Best Way To Get Around:
Marrakesh is a great walking city - there's always something to stop & see or buy - so you don't want to be constrained to a car.