When my nephew was that age and into geography DH and I came up with a game we called "Travels with my Aunt and Uncle." We got him a map of the United States and a set of small toy cars. We then came up with different "trips" we were taking across the country. He would locate the different cities, national parks, etc and find a route from one to the next using the cars to "travel" with us. He loved this so every birthday and holiday we would send him a new set of adventures. As we got more advanced with it we would send along toy planes, trains, boats, etc and have him fly from one location to another, pick up a car and drive to a river where he would catch a boat, etc. It was fun for all of us
