It seems that the dungeon has one scale and once you exit it, the knob is turned back a few clicks and the wilderness has another. The 10' square becomes the 25 mile hex. But I wonder if there is a way to tap into something in between. As a kid, I always loved those maps on the end papers of children's books that showed a locale that the book took place in (sort of like Winnie the Pooh and Watership Down, but I know there were better examples that I can't find now).
And any one who has done a little hiking knows the wilderness at a smaller scale is not just something you can breeze through-- there are ravines, rock fields, thickets, and bodies of water. I wonder if these could be laid out like a dungeon. I don't mean trying to constrain movement like video games do, with every tree acting as part of a wall. But, if you want to force your way through those thorns over there, you can but it will take time to hack through and giant rats love thorn bushes. Treasure can be present as well: abandoned shrines covered with offerings, magic berries, toad stools, the loot from the creature lairs etc. Were there ever modules that explored this idea and I missed them?
Update: Anyone trying this should have Zak's post on dungeons as required reading. There's a lot there, but re-reading it, I think he gives reasons why people don't often go this route. Sorry, I'd forgotten about that until my last post reminded me of his gigadungeon idea.