I'll set the stage with some pictures of the area. This is in the artificial swamp at the north end of Lake Vermilion, the water supply for Danville. When you first arrive, you have a view of this fairly nice observation tower:
(The funny looking blob in the sky to the left of the tower is not a bird, nor yet a plane, it is a speck of dirt on the lens, or perhaps on the sensor. I really need to do a better job keeping my equipment clean. Hopefully the shame of having to make this disclaimer will help.)
In addition to the observation tower, there is a nice floating boardwalk; it's only maybe a quarter of a mile long, but this is a minor county park in my poor county right here in central Illinois, not a national park, and I'm pretty impressed with it.
Here's a view of a chunk of the boardwalk from up in the tower:
I have a bunch more pictures to share, but I want to spend some time outdoors today, and this (as always) is taking way too long. I will try to post some exciting bird pictures this evening; I will get to them soon if not today.