Pig Fortress

A Pig fortress is what the pigs live in, in Angry Birds. They are what makes the levels hard. 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 in one level. However, they are still made of the regular mateials.

Terrains

 * 1) Plains (Worlds 1 and 4)1-1.png and ice.]]
 * 2) Deserts (World 5)
 * 3) Mountains (World 2)
 * 4) Sunset Mountain (World 3)
 * 5) Jungle (World 6)
 * 6) City (World 7)
 * 7) Clouds (World 8)
 * 8) Construction (Worlds 9-11 [based on themes from previous levels])
 * 9) Western (Worlds 12-14)
 * 10) Cave (Worlds 15-17)
 * 11) Cake land (World 18)