The trading post was on the border between Yardanari city-state Liruda and the Valatean Republic, not on a frontier with some wilderness. So also likely in the vicinity of major road if not right next to it.
View attachment 4101879
Somewhere around the blue/yellow line here where the three roads meet:
View attachment 4101866
and not that far from Amarath by the looks of it.
Well, except that I will add that the map is not an accurate type, satellite or topographic, but a stylization, through which, however, one can understand what and where approximately located. On those
“empty” places there are tons of all sorts of small settlements, villages, trading posts, etc.
I would also add that the main republican trade route is along the river through the towns of Nemeda - Amarath - Medosa - Valatea. Foreign trade is from Yardanar to Nemeda from the west, branching from Amarath north to the Alliance of Seven, then from Medosa northeast to the Dominion, and lastly from Valatea south to the ocean coast to Thesea (Dominion again).
These routes are usually bustling with life. Trade wagons and even entire caravans, along the rivers, merchant ships, and light
“river” patrol galleys. The road
“straight” from Amarath to Valatea is more of a remote wilderness, where few people live and few people travel. This is why there were only a couple of encounters noted cursorily in the descriptions, and otherwise Selene and the troupe now see only bushes, trees, lakes, hills... trees, well, yeah, there's a lot of trees. And anything else, um, not so much.
