OK well, I found out that if i use the cheat "UnlockAllMaps" it unlocks Longwatch Falls for me to travel to, but I'd rather not do that because it will disable the achievements. Sucks that there's no other way to modify the files to unlock the map than to resort to using the cheat. I suppose Steam achievements aren't all that important.
I even tried saving the game before the cheat, using the cheat and traveling to Longwatch Falls, then moving over the files I thought pertained to the Falls (exterior something or other) to my previous save, but that didn't work. Still couldn't click the name on the world map.
- Scrubbs