I think this is a fun idea. I just created a map for the players in a game I run that lays out the creation of a network of enchanted towers designed to harness, amplify, and control a nexus crystal (which in my world is a convergence point of lay lines and extra-planar energy). The map only has minor enchantments, mostly to preserve and protect it, but because it documents a magical process I think it fits the description of this challenge (it fits Gamerprinter's example #2 quite nicely), and if anyone is interested I'm going to post it over in the regional section for mapping.

I might do a new map for this challenge, but I'd like to go in a different direction, and I haven't been inspired yet with a concept.