Missile silos are large underground military structures built in the event of war during the Cold War era. About 500 are still in commission while many have been decommissioned and had their main weapon removed and their silos filled with debris and concrete. They are built to withstand nuclear fallout and are heavily secured to prevent unauthorized access. They often have advanced communication systems that allow for them to receive orders from around the country. They may also be stocked with food, supplies and ammunition. Missile silos also have heavy blast doors made of inches of concrete which are used to contain a blast once a missile is being launched, which could also be used to effectively seal off areas where zombies manage to infiltrate. With many remaining silos, the command center is the only surviving underground structure, while the actual missile silo has been filled and capped with concrete. Some silos are inside military bases themselves or big enough to function as one in which case they may have a vehicle and/or supply depot where there are trucks and lighter vehicles used for transporting equipment and personell, and also probably armored vehicles which could be used for defense.
- Lots of room for a medium sized group
- Only one entrance, making it easy to barricade
- Only one entrance, so if the Zeds break in, there's no other way out.