A few of my favorites, aside from OP's. Unfortunately as this thread has progressed, a lot of ppl have stopped providing the pseudo-scientific/mystical reasonings and are just listing game mechanics out of context. 320. Ancient Shaolin Monks live in the mountains. Wielding unearthly psychokinetic powers they reverse the flow of gravity and keep Mountain Streams and Rivers from flowing downhill. Unlike loincloth clad Men with clubs of immortality, The Shaolin Monks occasionally die, thus you will infrequently find Mountain Rivers. 321. Rumours of the Mountain Dwelling Monks scare the bejeezus out of everyone, thus all units will refuse to go near the cursed stone. 322. The underground Sorcerers (previous post) while warping city walls in and out of time, sometimes interfere with The Monk's Psychokinetic powers and rivers will suddenly appear in the middle of a grassland.