To get this view of the Moti Mahal (pearl palace) an attacker would have had to fight his way through five gates and would still have another two to go. I've seen plenty of castles in various countries but none of them (not even the greatest of the crusader castles, the Crac des Chevaliers) come anywhere near the Meherangarh fort for awe-inspiring impregnability. Walking up the hill to the fort is hard enough with all the gates open and no defenders to worry about.
Building of the Moti Mahal is usually attributed to the Raja Sur Singh which would place it at the end of the 16th century.