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: http://i.imgur.com/GrlkyNi.png