Placing AC2: Treasure of the Hideous One (1984)
by Lance DuncanI placed it in the obvious place on the river fork just west of riverfork keep(which you have to assume isn't there at the the time of the adventure) back when I did my webmap project. I added a second part to the blight swamp based on the adventure, so there is the upper blight swamp, then the achelos woods further south and even further south is the lower blight swamp(referring to lower and upper parts of the river. I made the upper blight swamp in a depression of land with poor drainage to accommodate for the swampy features.
as far as the whole "due west 7 days" first of all thats until they hit river which is downstream from where number 1 is placed on the adventure map. and also west is general term is you dont have a compass, maybe they started going due west from threshold, but due to the hills ended up heading more northwest. which brings me to the point of 7 days, if you account for slow travel times across hilly and forested terrain and that they had a baggage train, it can actually take 7 days to reach the achelos river
Of course all this doesn't really matter for me because in my home game I dont actually use this placement. In my dad's games the swamp was always the malpheggi swamp and so that is where I have to place it for my campaign.