Heatherstone Park is probably well known to the families of children who attend the adjacent Heatherstone Elementary School, but if you don't know it's there, it could be hard to notice.
It's basically invisible when you're driving by on Pflumm to the east, it's bordered by a pocket of secluded gated houses on the south, a thick bunch of trees block your view of it even when you're in the school parking lot on the west, and there is a bunch of "no man's land" to the north. You just have to know it's there, either by word of mouth, wandering down the path on the side of the school, or looking it up on something like Google Maps or the OPRD website.
So...does this qualify as a hidden treasure? After a visit to the park via bicycle (coming up from the Indian Creek Trail, which runs past about half a block south), I'd say yes!
The first thing I found, riding my bike in from the Pflumm sidewalk, was the trail that goes around the park. It features exercise stations, and winds along for about half a mile.
In the middle of the trail loop is an area that is allowed to grow kind of wild like the old prairie days, and there's also a strip of this in the "no man's land".
There is a shelter and a playground area, which I didn't photograph because other people's kids were there and I didn't want to seem creepy.
And there is also a pretty nice lake, with signs giving the rules about fishing.
All in all, this is a great park, with a number of nice features, which shouldn't be too crowded.