My local one (Hull) is one of the best attended. 450 there last time I went which isn't as often as I'd like to go. Nice mix of people there.
2 laps of the park lake - I was lapped the first time I went

there are some very quick club runners turn up. Seems to work quite well as in the start is very wide but goes to a 6' path after a few hundred metres, fortunately the runners stretch out a bit by then.