The Strong Holed

There are many small pockets of survivors but the biggest one and that is classed as a Strong Holed is the best  well protected is Alcatraz Island in San Fransisco CA. The reason it is the most well protected I because it is surrounded by water and was formerly used  as a prison so it could keep the zombies out and keep things in if needed. There most of Americas prised artifacts are held and some of its most prised people. It first started to be sued as a fortresses 3 months after the apocalypses were normal people just took there boats and went to the island for protection then the group grew and people still alive figured out it is a lot safer on the island than it is on the mainland the when more people came the started to spread to the other islands close by and soon a community on the island started and slowly society started to come back.