Cintos, the "lake bed calligraphy" may have been marked before, but your folder of oriented lakes is what I find interesting. Do you have any more to add to that? It is very reminiscent of the "Carolina bays" in the southeast U.S. and to another grouping of oriented lakes in southeastern Australia. Those lakes are described in this thread. I've found quite a lot about the Carolina Bays, but so far nothing about the Australian lakes. Your post is the first I have ever heard of the South African lakes. They are particularly interesting because some are being mined. Meteoric material?