Thx for the answers. Yes my question is about partisan activities but not for all swamp,desert,or mountain areas.Specifically some places on the earth hard to control or conquer ,like Tora Bora (Afgan Mountains),or Tuareg desert.,places give extra bonuses like Hayber pass.
Think about Communist China in game conquering is easy.In WW2 Japan or Nationalist China couldnot conquer there. This isnot good .Dont miss understood me.Game is perfect and this mistake is acceptable.There arenot much places like them.Maybe best description will be like this ;places cannot be controlled by any regular army because of geographic conditions and nature of native people.(One example too ;Vietnam)