I have a Mancs friend who runs regularly at Heaton Park. here's his review:
"The park run in Heaton Park is nice, but I think it's in the wrong direction. I've not done it with everyone else, but I do the route occasionally on my own.
It starts off at the back of Heaton Hall, which is a very wide, packed gravel path. The run then turns left and goes around the front of the hall before turning left again and heading down a long, gentle slope of wide tarmac path followed by a long, pretty flat stretch before turning left again by the boating lake. This winds just a little, but is still wide and flat tarmac. It then turns left again and starts up a quite steep slope, before turning left again onto a narrower path that goes downhill again, before heading up into a small wood and then down again to rejoin the big wide tarmac path from earlier at the bottom of the long slope.
You then do the longish flat again, but keep going around the back of the boating lake, which is quite wide, but mostly packed mud which can get quite wet. This curves around to the left, following the lake, and rejoins the route from earlier at the base of the long, steep slope. So the last kilometre starts with a long, steep uphill slog, before then going through the woods at the front of the hall, which is still tarmac and quite wide, but does undulate, and coming out to finish with a short uphill section and a longish, flat straight.
Personally, finishing with the long, gentle uphill slope seems like a much better idea to me than the long steep uphill slog, but there you go "