Ooh ggg,had a fabulous month there before dd was born. Can't work out why the place isn't overrun with the French!
Marrakesh is the only choice.Stay in a nice riyadh,check out the souks,the Djemma el Fna which is positively mediaeval-hennaartists,water sellers and snake charmers by day,fantastic food stalls by night.
YSL's garden (Majorelle) is supposed to be lovely,although never went, Racking brains for that lovely hotel Churchill et all stayed in...
Hang on,I'll get my LP...
(I would stay close to the square though for sheer atmospherics. Won't get the pool and gardens,but one doesn't really go to Marrakech for that.)