I was in a "treehouse hostel" in a tropical country (I don't want to get more specific than that). It was like one big 3 floor set of bunk beds. Everyone had an individual pod with a thin mattress over some slats in the floor. There were pods above, below, and next to other pods. The walls were just slats with gaps in them, and the floors were about the same. It was sturdy and I wasn't worried about it collapsing or anything, but it only barely qualified as a building. That was part of the charm as it was sold as a slightly upgraded camping trip in the jungle next to a river.
My pod was on one end of the top floor of the place. I could look through the gaps in my "wall" to the showers. They were 3 concrete buildings with 3 walls each enclosed by a long curtain. The curtain was *just* tall enough to cover most of the girls' nipples, but I could still get lots of good peeks as the girls lifted their arms to wash their hair, or when they would open the curtain to reach for their towels.
The gaps in the wall were thin enough, and the inside of the treehouse was dark enough, that you couldn't see through them from the outside. I spent hours staring through those gaps waiting for some good glimpses.
I remember one girl who was showering late one afternoon. It was the extra windy hour before a big rain storm, so the wind kept blowing the curtain off to the side. At first, she kept trying to make sure the curtain stayed closed, but she soon realized that it was a losing battle if she actually wanted to have a shower. There was no one else around the showers at the time, and she didn't think anyone could see her so she eventually stopped caring. I was treated to an unobstructed view of her entire shower from about 20 feet away. Watching her vigorously rub her thick, dark bush getting it all sudsy, then rubbing it more to rinse it off was such a turn on.
Most of the time I was there my "downstairs" neighbor was a dude, but the day before I left a cute girl moved in to that bunk. I had a nice view of her tits through the floor slats as she slept topless on my last morning. It was a nice parting gift, but I wish my plane ticket was refundable