Military bases are a given in terms of protection from the undead. This comes mostly from how the military and the government chooses to respond to the epidemic.
They are somewhat self-sufficient fortresses.
- A fuel reserve.
- MRE rations (Meals Ready to Eat).
- Training facilities.
- Machine shops.
- Independent power grids.
- Communication capabilities.
- Some or maybe a fully armed standard solid physical defense--(Most likely armed Military personal, who inhabit the base).
- Medical supplies designed to treat military-grade wounds
- Field hospitals
- A sealed off barbed wired fence or possibly a defensive wall perimeter
- A weapons and ammo vault
- A bomb shelter nearby for air raids which may staff important military personnel.
However, the main reason the masses flee to military bases are weapons and protection. A military base is going to be staffed with a full army of trained specialists who know how to handle a disaster scenario. However, this does not necessarily mean that they know how to deal with the undead. When arriving at the military base, be careful how you approach, as the military may mistake you for a zombie or "rioter", while keeping alert for anyone else trying to enter.
Many people will swarm to military bases, seeking protection. Although a sound idea, swarms of people can quickly consume the base's resources. An infected individual or a horde of undead lead by this rush can quickly overwhelm most standard military bases. In games, it is not by mistake that many bases are occupied by zombies. This will make getting supplies or making this your refuge very difficult.
Keep in mind that U.S. military bases of the present day are designed according to the most current threats. Most bases have a chain link fence topped with barbed wire to keep unauthorized personnel from entering and have gaps to allow for vehicular traffic. The primary purpose of the base's defensive posture is to defend against a small number of infiltrators and not an opposing army. With that being said, there are locations on every base that are designed for physical security and can be easily modified as a hold out against the undead.
Weapons are stored in armories that cater to a specific unit on the installation, with ammunition and ordnance stored separately in ammunition supply points.
WARNING: There are possibilities that any non-military personnel that try to enter a military base will be cleared to be shot. Be careful on how you introduce yourself.