Corn mazes are pretty good, but I'll be more impressed when I see some contour lines. :)
Many of GCO's maps are on 19th century industrial waste (dredged riverbed) moved by steam engines in the search for California gold.
A number of years ago, Swampfox wanted more control features for relays at Lake George. Building cairns was one option (he decided to build one at the top of a hill made of stones from the bottom of the hill, good training), but he also discussed building a charcoal platform. This resulted in some anxious discussion between us, due to my misunderstanding that he wanted to actually make charcoal (which we agreed would be a particularly bad idea).
All that would be required, I think, would be to flatten out a spot, preferably on the side of a hill, and scatter a bag or so of briquettes.
And then there is the set of maps along the M3, where all the interesting contour features were created by the Luftwaffe.