We probably drove under the Archway Museum a dozen times before we stopped to check it out. This is a great museum about the history of Platte River area. There is ample parking for RVs and they allow overnight parking.
archway.org
If you have the opportunity, it's a great stop!
The Archway - Kearney, NE
Visit the Archway in Kearney, Nebraska, and celebrate the American spirit of adventure! From the Oregon Trail era through today, the Archway’s family friendly historical exhibit tells the story of those who followed the Great Platte River Road and helped to build America.
archway.org
If you have the opportunity, it's a great stop!