Launch Complex 39 A
During the Apollo and Saturn V era, the launch pad had no permanent structures on top. Everything was carried to the pad via the Mobile Launch Platform. It wasn't until the Space Shuttle that the permanent Rotating Service Structure was added. Underneath, are two separate air systems that supplied oxyegen for living and mechanical systems. Historic Pad 39A is now leased by SpaceX.
Pad 39A Rubber Room
During the Apollo missions, precautions were taken for crew and worker safety in case of an explosion of the Saturn V. At the base of the launch pad was a 200ft long slide that would drop them into the Rubber Room, where they would make their way to an adjacent blast room. Crew and workers could strap themselves in to ride out a potential explosion. Provisions were available and they could stay as long as 24 hours before making their way out through an escape tunnel which would take them over 1000 feet away from the pad. Fortunately, the Rubber Room was never used.