It's difficult to miss the castle in the background; Lancaster Priory is to the right. The nearer steeple is that of a deconsecrated Congregationalist church now occupied by a pub.
The redbrick building and long slate roof in the foreground are parts of Mitchell's brewery, which closed a few years ago. I've always thought the brick building is quite attractive, with odd corners and extensive vegetation on the roof, but a recent assessment concluded that it isn't of especial architectural or heritage merit, and will probably be demolished soon, as this side of the city centre is to undergo redevelopment.