I've been looking at a lot of the maps around, and I see lots of awesome maps, but the variety of terrain features has been a little dry. I was wondering if there could be a challenge to create maps with unusual "real world" features.

For instance: Oxbow Lakes are an interesting feature of real-world rivers that I see very few of in fantasy maps in general. Glacial Valleys, Fjords, and other water features are all interesting and seem to be somewhat neglected.