A unique mod called Secret Rooms will allow you to create a secret room in Minecraft. In general, you yourself are free to create anything, but this mod adds a lot of hidden blocks, buttons and much more to the game.
Mod Secret Rooms for Minecraft 1.14.4/1.12.2
Use the new blocks to create traps, various secret rooms and other cool solutions.
1.14.4 – Secret-Rooms-Mod-1.14.4
1.12.2 – Secret-Rooms-Mod-1.12.2