I wrote this up for a book on the lifestyles of adventurers (as in how much do they cost and what repercussions are there). Well, it got really long and didn’t fit the book anymore, so rather than throw it out, I’m sharing it with you.
Let’s take Tim the Trapper for instance. Tim comes to the big city with his winter pelts in early spring. He makes a killing selling them to the furriers and he is richer than he has ever been before. Then he goes to the inn and discovers how much they want for a room. Several harsh words later, he decides that he is a tough guy and he would rather sleep under the stars than pay those prices. Evening comes, he settles down and has a nice night in the light woods about a mile from the city.
The next day, he explores the city, buying gear and replenishing supplies. He returns to his campsite, but this night it rains. The next morning, he continues his shopping, wet and not as happy. During the day, he meets Milo the Merchant. Milo is selling fire wood, and Tim cannot believe how much Milo is asking for pieces of wood. I mean, come on, they’re just lying around out in the forest. So Tim comes up with a plan. The little furry creatures are shedding and mating, so it’s not a great time to trap them. So he decides to stay here for a while. He’ll gather wood, bundle it and sell it in the city, just like Milo. So Tim brings a dozen bundles to the city, but only sells three. The next day, he lowers his price and only sells four. That’s when Milo spots him. “Hey Tim,” he says, “I notice that you’re trying to sell your fire wood. Tell you what I’m gonna do. Rather than both of us standing around here all day, you go out and get the firewood, and I’ll sell it and give you half.” Well, Tim isn’t a bookkeeper, but if Milo will sell 12 a day, and give half to Tim, then Tim will still be far better off than getting all of 3 sales. So the deal is made.
Throughout this time, Tim has been improving his campsite. First he set up an awning to keep off the rain. Then he built up the fire pit into something more resembling a fireplace. Then he put up some log walls. Before you know it, Tim has built himself a crude cabin in the woods. Tim sells his firewood to Milo for a couple of weeks, but Tim is getting hungry and he hates paying the huge prices in town for his food. So he goes off for a week on a hunting expedition and brings back enough meat that he can preserve some. He brings his firewood to Milo, but Milo has already found another sucker who will go out into the woods and bring back fire wood for him, and he only wants 40% of the profits, so Tim is out of luck.
Disgusted by the whole urban drama, Tim returns to the wilderness to continue his life of hunting and trapping, leaving his cute little cabin behind. If Tim had succeeded, he would have left his cute little cabin in the wilderness behind.
The point of this little theater was to explain that in the wooded areas around fantasy cities, it would be common to find campsites and even cabins. Some might be in use, while others would have been abandoned. Any woodsman with the slightest bit of survival training would easily know how to build some manner of shelter, even if easy to find caves were not scattered across the countryside. While these shelters would likely fall in on themselves after a couple of years, there should be enough of them around that they would make common random encounters in the wilderness. If you need to, think of them as homeless shanties. They may not be everywhere, but if you know where to look (likely close to the stream), you’re going to find them.