Creative writing practice – describing a dystopia

Looming out of the mist beyond the gateway, the battersea power station
rose, it’s derilect chimneys no longer billowing smoke, it’s halls put to a new use. A better use. Two soldiers stood guard, in the shadows almost within touching distance of the monolithic building. A car drew up to the silent gateway, the driver flicking out his ID to the solitary resident of the booth. Another pair of soldiers stood guard behind the gate, alert for the sign from the booth signalling to stand down. After what seemed like an age of silent scrutiny, the go ahead was given. As one, the soldiers stepped back leaving a clear path across the bridge to the innermost gate of the sanctuary, the final bridge swinging open. The car pulled out onto the bridge, prowling silently onwards.