Travelers upon the [Insert Appropriate Name so as to Invoke Terror in Your PCs’ Hearts] River will come upon a oftentimes welcoming, yet altogether strange site before they head, for whatever reasons (we’re not judging), into the sodden wastes of the [really nasty swampy, ruin-strewn lands upriver].
Ongnub the River Warden is a half-orc who claims to have inherited his title and hut from the previous river warden. Whether he is telling the truth, of course, is entirely up to your PCs preconceived bias against his race.
This is an older map I made in attempt to nail down an exterior style. I’ve since changed it up a bit but thought this was still worth sharing.