The Transforming Room
Hmmm, this is, in my opinion, is quite unusual, as well as the original card, which turns to the bathroom.
I rarely see any Redstone maps, and here such an unusual card in its concept. Saying nothing more here, because if you want to know how things work there, you will easily learn it having dug deeper floor.
version: 1.1.0, 1.0.6, 1.0.5, 1.0.4, 1.0.0, 0.17.0, 0.16.0