It's marked on the map here.
A workable approach to get in is to move over the terrain until you're in the narrow red area (i.e. above the tunnel itself), then follow the red area to reach one of the entrances at each end.
The Wolfs Throat is the tunnel, don't go all the way through it to the base.
The easiest way to find it is to follow the road over the bridge leading away from the port (the one you had to stop being blown up in the previous mission).
I really should do something about this signature.
Aaaah thanks very much for all your help guys! I have been able to go in and serve justice so we're all good 
Thanks again.
Hey guys
I'm playing in Striga at the moment and cannot for the life of me find the Wolf's Throat. I know you have to go to a tunnel in the Council base, and that takes you there but I can't find said tunnel anywhere!
Any directions? Thanks!