This month's challenge comes to us courtesy of foremost:

Each participant takes a map that they have done before, but goes back to its initial steps and changes it so that the land and the water swap places. Lakes become islands, continents become oceans, etc...

The maps would be graded based upon two factors:

1) Straight up creatively and skill, as normal, and
2) How well the map complements it's source.

The new map might use the same town names, or, if the cartographer is confident [s]he can pull it off, matching landforms (mountains to underwater trenches, forests to lagoons, etc...). Ideally, the two maps would be presented next to each other for the final WIP, but due to the size limit here, that might not work. Anyway, each cartographer would be required to post clear reference to the source map they were using.
A great idea, and one that should be fun to do. I'm going to slightly alter/expand foremost's idea - the map 'Inversed' should be one the cartographer has drawn themselves, but it doesn't have to be a strictly 'flip land for water' map - it could be dungeon halls and rooms traded for town/city streets, for example.

As usual, title your threads: October 2015 Challenge: << your title here >>

Don't forget to put the hashtag ### Latest WIP ### in front of all WIP pictures.

The Challenge will run to approximately the end of the month (probably sometime early in the day on November 1st) after which there'll be three days of voting and then that most Holy of Holies: the Awarding of the Golden Compass! (And the love and rep of your peers.)