The 100-acre park is what remains of Spokane's Expo '74. Sprawling across several islands in the Spokane River, near the falls, the park was developed from old railroad yards, where the stone clock tower of the former Great Northern Railroad Station, built in 1902, stands in sharp architectural contrast to the Expo '74 building. One of the modernist buildings houses an IMAX theater, and the opera house occupies the former Washington State pavilion. The outdoor Ice Palace is open mid-October through March. A children's train chugs around the park in summer, and a 1909 carousel, hand-carved by master builder Charles I.D. Looff, is a local landmark. Another icon here is the giant red slide shaped like a Radio Flyer wagon. Other attractions include a sky ride over Spokane falls, mini-golf, and amusement rides.