Tennessee's Oak Ridge National Laboratory was such a well-kept secret during World War II that most Americans still don't know it sits off one of the busiest highways in the South.
Streams of vacationers whiz by the site that enriched uranium for America's first atomic bombs on their way to Great Smoky Mountains National Park -- the most popular in the nation, just south of Knoxville off Interstate 40. Each year about this time, Oak Ridge holds a Secret City Festival, crying out to potential tourists. "They don't even know we're here," said Katy Brown, president of the city's convention and visitor's bureau.
But a spotlight might soon shine on the Oak Ridge lab and two other largely forgotten Manhattan Project sites on the approach of the 70th anniversary of the general order that established it. The Obama administration is supporting bipartisan legislation in Congress that would designate major sites in Oak Ridge; Hanford, Wash.; and Los Alamos, N.M., as national parks, paving the way for wider exposure for the aging laboratories that altered world history -- and, some say, darkened it.
The Hanford site produced plutonium. The Oak Ridge site enriched uranium. And workers in Los Alamos used those materials to assemble the Little Boy and Fat Man bombs dropped on Japan, forcing a Japanese surrender and ending the war. Some 200,000 civilians in Hiroshima and Nagasaki perished.
The Advisory Council on Historic Preservation called the bomb's creation and use "the single most significant event of the 20th century" in advocating for the preservation of buildings once scheduled for demolition.
The president of the Japanese American Association of New York is not as nostalgic. Any commemoration of the sites, said Gary S. Moriwaki, should educate visitors "on the devastating effects of the bombs dropped on" Japan.
"One should reflect on the words of J. Robert Oppenheimer," Mr. Moriwaki said. " 'I am become death, the destroyer of worlds.' " Oppenheimer, a physicist, guided the project at Los Alamos and has been called the father of the atomic bomb.
Today, thousands of scientists continue to work in those labs on unrelated research, giving life to pioneering technologies now used for the Mars rover, chemotherapy, whole-body X-ray scanning at airports, high-speed computers and biotechnology -- a legacy of the brilliant scientists who worked at the sites during World War II, Energy Department officials said.
"You can't deny the impact nuclear weapons have had," said Micah Zenko, a fellow at Council on Foreign Relations who specializes in nuclear policy. Mr. Zenko said preserving the Manhattan Project sites makes sense. "It's a part of American history that most people forget."
Each site has some nuclear-waste contamination and those sites are undergoing cleanups involving up to 30,000 workers under multibillion-dollar contracts, said David G. Huizenga, senior adviser for environmental management at the Energy Department.
Mr. Huizenga said he's certain tourists can safely visit any Manhattan Project site. "Tours will steer well clear of contaminated areas. You would have to be directly digging up the waste to be at risk of being exposed by it," he said.