Over the past couple of years I've seen quite a few 'high-level' objects over Sheffield - usually static, but occasionally moving, and usually quite bright/reflective - one almost looked like a tea-tray. One day a few of us were working on a roof and saw an object hovering over the centre of Rotherham, and it must have been in one position for over two hours before very slowly moving off toward Doncaster - it appeared to be very high, rather than very small, but it's difficult to tell with a cloudless sky. After lunch we went back up and within half an hour it was back again - roughly the same spot in the sky, and about the same duration. I dunno if all drone batteries have the same lifetime, but that seemed quite a long time in the air - if it was a drone of course. If it was an advanced civilisation then fair enough.
The Tinsley area was famous for 'lights in the sky' long before drones were invented :-\