There are some interesting climbs around and near Glasgow. The Crow Road between Lennoxtown and Fintry (both directions), the Tak Ma Doon between Kilsyth and Carron Bridge, and a new one to me, Glen Fruin Road (the narrow one) from Faslane to Glen Fruin itself. Here it is! Those red parts are between 10% and 13%, only just about feasible on my 46/18 69″ single speed gear. I was standing on the pedals for the complete climb, about a mile.