A museum exhibit profiling a largely untold aspect of a turning point of the 20th century opened today in the U.S. capital, sponsored in part by Bechtel, a global leader in engineering, procurement, and construction. The new exhibit, called Secret Cities: The Architecture and Planning of the Manhattan Project, examines the innovative design and construction of Oak Ridge, Tennessee, Hanford, Washington, and Los Alamos, New Mexico; looks at daily lives within the cities, and addresses each city’s development since the conclusion of the Project.