The Sunsphere is a 266-foot (81 m) tall hexagonal steel truss structure located in World's Fair Park in downtown Knoxville, Tennessee, United States.

It weighs 600 short tons (540 t) and features six double steel truss columns in supporting the seven-story sphere.

The tower served as a restaurant and featured food items such as the "Sunburger" and a rum and fruit juice cocktail called the "Sunburst".

[7] On Sunday, May 14, 2000, nuclear weapons protesters scaled the tower and hung a large banner saying "Stop the Bombs".

During construction of the Convention Center, the observation deck – which the city had briefly reopened, still sporting the original World's Fair-era displays and explanations of the panorama – was closed while the tower was commandeered by the Knoxville Public Building Authority as offices for, quite literally, overseeing construction of the Convention Center.

It eventually closed, however, and real estate investor Tony Capiello opened Icon Ultra Lounge in its place, investing $450,000.

[17] Bart and three friends (Nelson, Martin, and Milhouse) travel to Knoxville to visit the World's Fair, only to learn they are over a decade too late.

[18] Nelson then throws a rock at the Sunsphere, causing it to topple over and land on top of their rental car, destroying it and stranding them in Knoxville.