How to make hidden doors in Minecraft
The plan below shows every block except the Item Frame, which you hang last.

An Item Frame is a small frame that displays an item on a wall, floor or ceiling.
It is made with the Crafting Table from 8 × Stick and Leather.
Eight sticks around Leather make one. Put an item in it, then use it again to rotate the item; a comparator behind it reads that rotation, which makes combination locks. Maps placed in frames build wall maps.
8 × Stick + Leather → Item Frame
// Slots with several items cycle through every accepted option.
The plan below shows every block except the Item Frame, which you hang last.
maps of neighbouring grid squares, at the same level, line up exactly when you place them in Item Frames side by side.
An elytra is found on the ships next to some End Cities , in an item frame.
At the Crafting Table: 8 × Stick and 1 × Leather give 1 × Item Frame. Sold by Villager: Cartographer (Expert).
It displays items and maps and powers rotation locks. It is an ingredient in one recipe: Glow Item Frame.