For this tutorial, he took a regular book shelf and mounted it onto a wooden door, with the door itself ... he added some caster wheels hidden in the bottom as support. As for the (un)locking ...

The other end of the table is supported by a frame on the wall, which also contains several shelves for small objects ... piece with no clue as to its hidden functionality. It’s a fun build ...

We’re spotting hidden doors everywhere at the moment – connecting bedrooms to en suites, kitchens to pantries, and leading from sitting rooms to home offices and secret reading nooks.