We visited Carney Marsh last summer as a part of the Polk County Geocaching Challenge; it is a cool little spot in Ankeny with diverse wildlife and flora.
You can see more specific details on the Carney Marsh page below or check out its location on the interactive map.
I was surprised at how urban this felt, it was tucked right off a road.
Typical marsh views, lots of cattails and swampy spots along the trail.
The path itself is paved and shaded in spots, connecting to several main trails going in both directions.
We saw so many turtles off to one side! You can see the subtle little lumps along the logs here.
How cute is this tiny slug!
Look at that fungus!
Very diverse wildflowers in lots of different shades, I think the orange ones were my favorite. 
We initially thought those red patches were a vine, until we got closer and realized they were bugs! So gross/pretty.
I was surprised at how many different things there were to look at in such a short section of path, but Carney Marsh had a lot of birds, animals, and flowers to observe.