This is the fortress-town in the center of Bukhara that housed the nobility and many of the government buildings responsible for the functioning of Bukhara. Mosques, royal courts, apartments, jails, torture chambers, and everything else you'd need to run a khanate on the silk road. While much of the Ark is in ruins, after having been bombed by the Red Army in the early 1920's, it still is a very impressive sight.
The Ark, Mirzo Khait Street, Bukhara, Bukhara Province, Uzbekistan (Directions)