The Australian International Airshow is a major aviation event at Avalon Airport, between Melbourne and Geelong. It brings military aircraft, aerobatics, aerospace displays, and large crowds to the flat airfield landscape north-east of the city.
This is a calendar-dependent POI: excellent if your visit lines up with the show, irrelevant if it does not. Plan transport, tickets, sun protection, and patience, because the scale is much closer to a festival than a normal museum visit.