Oh, like the description of the fence would change depending on what’s on the other side? There are various ways to do that, some of which would be more or less efficient depending on the number of locations where the fence shows up. If it’s only a few, I’d just have the description of the fence include some if… otherwise if… clauses depending on location. If it’s more than that, you can just do something like this too:
The pasture is a room. The fence-desc of the pasture is "Here's what you can see through the fence in the pasture." The hill is east of the pasture. The fence-desc of the hill is "Here's what you can see through the fence in the hill." The dell is south of the pasture. The fence-desc of the dell is "Here's what you can see through the fence in the dell." A room has some text called the fence-desc. The fence is a backdrop. It is everywhere. The description is "The wooden fence affords a view of the neighboring countryside: [fence-desc of the location]".
(If the multiple-fence thing you’ve got going is working for you, I wouldn’t change it, just sharing since you said this was your first idea)