Hidden Rooms, Secret Passageways, Disguised Doors...
A Trap door to subterranean tunnels beneath a Scottish Castle...Whee! One of the quaintest features of the castle is what’s known as the laird’s lug. “The laird [proprietor] of the castle needed to have somewhere to hide should the castle be attacked. It’s between floors, so you wouldn't know it existed.”
Necessary hardware for hiding doors within bookcases, etc...
A child's "secret" reading nook hidden behind a shallow bookcase door...
Q