A couple of days ago I came home through the local park and it was crawling with two engines' worth of firemen because someone had reported a strong smell of smoke.
15-20 years ago they put in astroturf 5-a-side pitches along with a little changing room building, which has a woodburning stove as was the fashion of the time. I've only noticed it this month because it absolutely stinks. Maybe they're burning something they shouldn't.