A short story... 14 years ago the only aerial imagery we could trace from was provided by Yahoo, which was okay for some cities. In the North East you could tell where Durham was because the green splodges were broken by a grey splodge. I made my best attempt based on walking around buildings with a garmin GPS and sketching on a clipboard the buildings relative to the paths I walked. Can you believe I was crazy enough to also attempt the outline of Trevs college? Anyway, technology has moved on as has support given to OSM. I have now adjusted the building outlines of Grey College.