On the edge of the former American parade grounds, this well-presented museum details the history of Clark from 1901 up to its development of the Freeport Zone. It includes some great military memorabilia, photos and displays on Mt Pinatubo's dramatic eruption. and info on the indigenous Aeta. A highlight is the 4D theatre screening four times a day.
While you're here take a stroll around the peaceful Parade Grounds, ringed by historic barn houses built in the early 20th century that served as former residences of US soldiers.