Secret Construction Built in the late 1950s, the bunker was designed to house the U.S. Congress during a nuclear emergency.12 Public Revelation The Washington Post exposed the facility in 1992, ending its classified status and prompting tours for visitors.345 References greenbrier.com ↩ congress.gov ↩ washingtonpost.com ↩ nps.gov ↩ en.wikipedia.org ↩