Polluted Forest is a bad design idea

Just arrived in here and did like 14 sorties. Obviously, knowing the game I used a cheap cradle and weapons too but you really have to tell me how you're supposed to reach one of the 2 investigations (the southern one). Paced all the way and all I could find were walls and hordes of mobs destroying you without even understanding what happened.

So yes, please, after venting could you guys please help me with that quest? I just wanna forget this map so quickly