We see two Nike Hercules missiles on rails. The missiles were moved in this position along the rails to launchers that could lift them to a vertical position for launching.
The open doors lead down a stair way to the underground missile storage area.
The low yellow structure is the top of the missile elevator that lifts the missiles from the underground missile storage area to the rails and launchers.
The elevator is in the "down" position, and steel doors cover the hole into the underground missile storage area. When the elevator is "up", you can see the launcher that is placed on the elevator. The missile can be fired from the elevator launcher, or moved to other launchers.
Bud Halsey explains:
With the extremely large thrust generated at the moment of firing, the missile, and its trail of flame, is not near the elevator for more than a split second. Remember, this missile goes off like a bottle rocket, not like the space shots we see on TV where the rocket seems to burn on the launcher for a long time before it begins to rise slowly off the pad. "
The radars and the battery control were actually on the top of the hill in the background. We cannot drive to the top of the hill, so the displays of the radars, "battery control van" and "radar van" are in the missile assembly area near this launcher area.