There’s something about analog development materials. Take, for example, these Legend of Zelda original design documents. Hand drawn on paper, they are still a sight to see.
Nintendo UK recently uploaded a host of these originals on its official site.
Here is Takashi Tezuka’s skull room drawing, with a comparison to how it appeared in game.
Another one from Tezuka.
This drawing was done by Shigeru Miyamoto.
He did a nice job of coloring the walls! Oh, and making this game.
Check out this world map and more drawings below: