Ah, so it's that easy. Probably could have found that on another cave tile on another map. Thanx. :D
Decided to take my Route 411 dislike into my own hands as well; it never made sense that so much terrain on an overworld map was set for wild encounters (not even grass), so made only the grass produce encounters. If I ever find a way to do deep sand, I might replace grassy areas with that and make it look more - well - realistic, making that the encounter area. :D
I still don't get how so much grass grows on a mountain top in there...
How do you fix the tile behaviour in AdvanceMap? I can do things like changing around parts of tiles for transparency, but not sure if I can set the "wild" flag. I'd kinda like to change that in the desert of Route 411 as well.