During the War, some governments were able to seal off some, or all of their country to keep areas well fortified, well supplied, and possibly self-sufficient (producing all of their food and supplies within the zone). Some of these areas were mandated evacuation centers that the rest of the country was ordered to relocate to.
There were apparently four effective methods to build safe zones.
1. Restrictive Quarrantine - to prohibit ALL refugees towards the beginning of the war (Examples: Israel,).
2. Island Terrain - a retreat to a smaller land mass with a less dense population would be easier to defend from ocean drifting zombies as well as sporadic internal outbreaks from refugees already accepted and infected (Examples: Tasmania, Ireland, Cuba, Taiwan, Madagascar, Vancouver Island, Hawaii, and Puerto Rico).
3. Mountain Ranges - usage of natural geographical boundaries to limit zombies to a relatively few number of easily defenseable choke points (Examples: Western North America, Scotland, Chile, Tibet and surrounding areas, and possibly Spain and Italy).
4. Building a Wall - Example: Israel
Also there were many types of safe zones chosen by a country:
1. Classic Safe Zone - a sector of ones country, usually seperated by a mountain range or river, and later purged of zombies within. In some cases, large, well-stocked, and defensively capable castles like Windsor were used.(Examples:Great Britain, nearly every safe zone)
2. Continental Safe Zone - a general retreat used by more than one country, due to the fact that there may not be enough military or materials left in the country for a moderatley sized safe zone. (Examples: The Himalayas, and possibly the Alps; apparently the Rockies)
3.Total Evacuation - When a certain country is too overpopulated and is blocked in, and is forced to evacuate. (Examples: Japan)