Oak Ridge is a city in Anderson and Roane counties in the eastern part of the U.S. state of Tennessee, about west of downtown Knoxville. Oak Ridge's population was 31,402 at the 2020 census. It is part of the Knoxville Metropolitan Area. Oak Ridge's nicknames include the Atomic City, the Secret City, and the City Behind the Fence.
In 1942, the United States federal government forcibly purchased nearly of farmland in the Clinch River Valley for the development of a planned city supporting 75,000 residents. It was constructed with assistance from architectural and engineering firm Skidmore, Owings & Merrill, from 1942 to 1943. Oak Ridge was established in 1942 as a production site for the Manhattan Project—the massive American, British, and Canadian operation that developed the atomic bomb. Being the site of Oak Ridge National Laboratory and Y-12 National Security Complex, scientific and technological development still plays a crucial role in the city's economy and culture in general.