Now a National Historic Landmark, the Titan Missile Museum makes for a sobering visit. During the cold war Tucson was ringed by 18 of the 54 Titan II missiles maintained in the United States. After the SALT II treaty with the Soviet Union was signed in 1979, this was the only missile-launch site left intact.
Guided tours, running every hour on the hour, last about an hour and take you down 55 steps into the command post, where a ground crew of four lived and waited.
Among the sights is the 103-foot, 165-ton, two-stage liquid-fuel rocket. Now empty, it originally held a nuclear warhead with 214 times the explosive power of the bomb that destroyed Hiroshima.