Not sure if this counts, but a buddy and I found a secret extension to his shed when we were teens. It was a sliding wooden door behind a woodworking shelf (th

Not sure if this counts, but a buddy and I found a secret extension to his shed when we were teens. It was a sliding wooden door behind a woodworking shelf (the door blended perfectly with the handtool holder wall). The room was about 3m by 2m. When we found it, it was empty and had hooks on the ceiling with two power outlets. We didn't tell his parents and thought it was a "cool" after school hangout spot. A few months later, we went back and a new shelf with weed plant cuttings was in the room. My buddy asked his dad and it turns out he had been growing a few weed plants hydroponically for the prior few years.