A giant theme park. A full-blown, $2 billion theme park. We have the only known giant leg lamp... A giant theme park along Route 66 would have fit right in. Check Out Oklahoma's Canceled Theme Park American Heartland Theme Park was supposed to be the latest huge investment for the Sooner State. Gallery Credit: KelsoOklahoma's Best Motorcycle Road Trips Since motorcycling is practically a year-round thing in Oklahoma, anytime is a good time to start planning your next road trip.