Accessing south Crestwood, Dragon Age Inquisition

Can someone please help me make this game a bit less infuriating and time-wasting than it is, by explaining how I can gain access to the southern part of Crestwood? I'm trying to do "Here Lies the Abyss", and cannot go remotely close enough for the walkthrough videos to be useful—they assume that I already arrived at Hawke's spot.

Here is a screenshot of the zone's map for me with the fog-of-war I couldn't access:

Solution 1:

South Crestwood becomes accessible after you get a certain way into the main quest for that area. You should have received a quest as part of this to recapture the old fort, which you'll find if you follow the road south out of Crestwood.

Once you've taken the fort, you can access the controls for the dam and drain the lake, which gives you access to the next plot area. It also gives you access to the route into South Crestwood.