If pushed for time, the must-sees are, in order of importance, the Harem, the Treasury, and the Pavilion of the Holy Mantle.
The Treasury is still used as a treasury to this day so you must see it.  
mnli hypothesis: The Treasury is still used as a treasury to this day so you must see it.   premise: If pushed for time, the must-sees are, in order of importance, the Harem, the Treasury, and the Pavilion of the Holy Mantle.