Construction -- consisting of a large concrete bunker lined with steel plates -- was begun at Sary Shagan .
The facility was far from complete when the Anti-Ballistic Missile Treaty was signed in 1972 , and these efforts ended .
Construction -- consisting of a large concrete bunker lined with steel plates -- was begun at Sary Shagan , but the facility was far from complete when the Anti-Ballistic Missile Treaty was signed in 1972 , and these efforts ended .