Just off of I-19, south of Tucson, is the Titan Missile Museum. There is a nice museum and gift shop. The tour is very interesting and informative. Since most of the silo is below ground, there are steps to descend to the control room. Those who cannot make the steps, travel to the control room via an elevator. The tour guide takes you through the steps required to launch a missile. After the control room tour you can wander the above-ground sites. This is well worth your time.