Pig Fortress

A Pig fortress is what the Bad Piggies build to protect themselves against and slow down the Birds from retaking their eggs. Pig Fortresses can be in any terrain: Mines, Jungles, Clouds, Normal Terrain, Construction sites, Desert, etc. Most of them are buildings, but some are seen to be methods of transport, for example, a tank-shaped structure in one level and wooden cars in a Golden Egg level. They mainly include materials such as ice, stone, and wood. They eventually get stronger in the later levels. In Angry Birds 2, it is set mainly in the air with plains in Cobalt Plateous levels, Bamboo in Forest Levels and City in Pig City levels.

Terrains

 * 1) Plains (Worlds 1 and 4)1-1.png Glass. This famous structure is also known as Poached Eggs 1-1.]]
 * 2) Deserts (World 3 and 5)
 * 3) Bamboo Gardens (World 2)
 * 4) Jungle (World 6)
 * 5) City (Worlds 7 and 11)
 * 6) Clouds (World 8)
 * 7) Construction (Worlds 9-11 [based on themes from worlds 1-7])
 * 8) Western (Worlds 12-14)
 * 9) Cave (Worlds 15-17)
 * 10) Birthday (World 18-19)
 * 11) Bad Piggies Theme 1: Ground Hog Day (World 20)
 * 12) Bad Piggies Theme 3: When Pigs Fly (Worlds 21 and 22)
 * 13) Beach (Surf And Turf Levels 1 to 15)
 * 14) River (Surf and Turf Levels 16 to 30)
 * 15) Stormy Mountainside (Surf and Turf Levels 31 to 45)