One of the designers over at TGC wanted to incorporate a dry pond into a build, a decent attempt considering the tools given, but looking more like a neglected bunker. (pic) another guy posted a real life pic of a dry pond bed complete with discarded tyre, i fancied the challenge so had a go...
GNCD dry bed
Course forge dry bed
5 min job, It really is amazing what you can do with CF, and to think we are only scratching the surface.