Maybe my world needs more giant lakes in deserts.
io9 sent me to Discovery News, which gives the story of a lake the size of Lake Michigan that was once in ancient Egypt. The lake was pre-historic, it seems, so it didn't influence Egyptian civilization. But what if that lake was there in my fantasy Mediterranean? Would it de-emphasize the importance of a place like Cairo? Would it make land routes through the Sahara more feasible? Would it have vikings and/or pirates?!!??! My head is swimming with possibilities.
And, yes, expect me to try my crude cartography skills at dropping a blue blob in Egypt very soon. But today's a busy one. . .