My favorite location to walk in Grand Island, Nebraska is Hall County Park. Why? The trees! It has trees, big trees, lots of trees. The path around the park is about a mile, and there are two other trails: one around the Stuhr Museum property, and a second trail that takes you to the Walmart.
All trails are very peaceful. If you feel adventurous, you can take one of the many trails into the woods. If you need a rest, there are plenty of swings and picnic tables. The restrooms in Hall County Park are some of the cleanest public facilities I have seen. Yes, they are ranked right up there with Chick-fil-a for cleanliness.
A word of caution. Watch out for motor vehicles, bicyclists, and wild turkeys.