This is basically a KOA Kamping Kabin. It had two sets of bunk beds inside (twin over twin, and twin over double), a fan, and electric lights. No heat, no air, had to use the comfort station facilities. They placed it on 1205 as an experiment. You could rent it for $15 over the cost of a partial hookup site. This was probably about 10 years ago. Apparently the experiment failed and they moved it out to an area near the old swamp trail to use as an "interpretive cabin" for the YES series of youth education programs. Now it is just for storage and reportedly has speakers that can be fired up to hear wishes from for the buggy rides.
From Jeff Spencer's site:
What is this I hear about a real cabin at Fort Wilderness?
There was a single real cabin on site 1205 that was available for guest booking. Unfortunately, it has been dismantled and moved to another location within the campground where it serves as an interpretive center and is no longer available for guest reservation. It was a small cabin, I estimate maybe 12 by 15 feet, which contained two sets of bunk beds. One set was a twin over a full size bed, the second was a twin over twin; therefore, the cabin slept 5. There was electricity and a fan but no heat or air-conditioning. There was no sink or toilet in the cabin. Guests had to use the comfort station. There was no maid service and guests had to bring their own linens. The rate for the cabin was $15 over the going rate for a partial hookup site. Guests that stayed there all seemed to like it but I guess Disney didn't consider the test a success.