Dayton has the world’s largest military aviation museum. It houses over 300 aircraft across four hangars organized by time period. There are planes from the two world wars, the anti-communist wars in East Asia, the latter decades of the cold war, and experimental aircraft. The National Aviation Hall of Fame is also inside the museum. The museum has American and foreign airplanes that it captured from its many wars.
It has an odd collection of non-aviation-related artifacts like the Berlin wall and a Holocaust gallery. The next nearest piece of the Berlin wall is only 50 minutes away in Cincinnati in front of the National Underground Railroad Freedom Center.
There are must-see aircraft for those in a hurry. Go inside a C-124 transport plane through its open jaw. Look inside the cockpit of a full-size Space Shuttle Trainer. Walk through the fuselage of a B-29. Sit in one of the many real cockpits of fighter jets. You could buy your way into a simulator, but at the entry price of free, I don’t think you need much more to be wowed in this museum.