Located at Wright-Patterson Air Force Base, 6 miles northeast of Dayton, this huuuuge museum has everything from a Wright Brothers 1909 Flyer to a Sopwith Camel (WWI biplane) and the 'Little Boy' type atomic bomb (decommissioned and rendered safe for display) dropped on Hiroshima. The hangars hold miles of planes, rockets and aviation machines. Be sure to visit Building 4 for spacecraft and presidential planes (including the first Air Force One). Plan on three hours overall; aviation buffs should allocate longer.
Buildings 2 and 4 have interactive flight simulators that will blow your mind. Tickets ($8 to $16) are required.