East (directly away from the river is the earthen slope (where Balter has commented is a death trap.. danger of landslide)
North (upriver) is the rocky climb - along a stretch of whitewater rapids on the Shrike river. This is the direction the boot tracks are heading.
South (downriver and toward the bandits' watchtower) is relatively level ground less foliage, standing boulders, and small groupings of trees. This is the direction in which you've spotted the collapsed stone structure.
The "bad smell" is coming from somewhere east, southeast, or southward.
It looks like you are going north.