Expo '74 was an environmentally themed World's Fair hosted in 1974 by Spokane, Washington, the smallest city ever to host a World's Fair. Environmentalism is activism aimed at improving the environment, particularly nature. ... Worlds Fair is the generic name for various large expositions held since the mid 19th century. ... 1974 is a common year starting on Tuesday (click on link for calendar). ... Spokane (pronounced ) is the county seat of Spokane County in the State of Washington. ...
Many of the structures built for the Fair are still standing. The United States Pavilion now houses an IMAX theater; the Washington State Pavilion became the downtown Opera House. The Expo site itself became the 100 acre (400,000 m²) Riverfront Park, containing the U.S. Pavilion and a clock tower (part of a Great Northern rail depot that was demolished for Expo '74), which are prominently featured in the park's logo. IMAX (for Image Maximum) is a film projection system which has the capacity to display images of far greater size and resolution than conventional film display systems. ... A separate article treats the Great Northern Railway in Britain. ...