(GMT)05 SEP 2016 THOGOO:
Iowa is generally not flat, most of the state consists of rolling hills and this makes some roads quite scenic as below.
The below scenic route(Great River Road) is from Lansing to Guttenberg.
It is suggested that you stop by Pikes Peak State Park. This park boasts one of Iowa's most spectacular views across the Mississippi on the highest bluff along the river.