While hanging around i stumbled on something surprising. If you enter the game's console, write "maplist" and select the map "m4l0.bsp", you'll play a hidden mission not found elsewhere in the game (till now i did not found it). It's a very diffrient map, with totally open terrain and and this area is full of dogs. One little warning don't enter the water! It is impossible to exit it and you'll only end up stuck.
Ahh! ther you have it ,a very differnt map from others !!!!