This post here on Tactile Maps at Telecanter's Receding Rules clued me in to the existence of tactile maps. It's an idea I was not aware of and a great way to provide "treasure maps" in dungeon settings that could be made by folks that don't require ( or simply don't want to be given away by ) light. One feels a series of bumps, notches and symbols carved into a device to find their way.
Here's a sample Tactile Map Key and a Tactile Map created according to the key:
Such a Tactile Map could be left hanging on a peg or inserted into a cavity carved to hold the tactile map if it were a mobile device. Such a map could also be incorporated into a larger mostly immobile sculpture, hidden in decorative carvings or etched on an another item.
The sample map describes this route:
From starting point take first left turn.
Travel about 120 feet then take the right turn.
Move 60 feet, beware of trap and pass through door.
Turn left and pass through portal to descend.
Take 1st left and travel about 300 feet
Enter the portal and you are there.