Dayton's most popular attraction also ranks as the world's largest and oldest military aviation museum. Sprawling over 10 acres of indoor exhibit space, this gargantuan institution features more than 300 aircraft and missiles, some of which visitors can climb aboard. In the Early Years Gallery you'll learn the history of flight and the principles of aeronautics. The Modern Flight Hangar is layered with post-World War II aircraft of every shape and kind; a flight simulator here takes visitors for a virtual ride.