I'm not particularly attached to 5% - it's just that I wouldn't want a Natural Wonder to make too much of a difference to stability. On the other hand, perhaps we could attach the stability bonus to culture? I.e. Mount Fuji gives +10% stability if Japanese culture is present in the city (I imagine we could link most Natural Wonders with cultures). Perhaps, but why monasteries as the 'needed' religious building? Maybe temples would make more sense - i.e. worshipping the mountain. Alternatively, we could have special 'shrines' that can be built if the Natural Wonder is present that gives the bonus - i.e. a 'Mount Fuji' shrine, giving +1 in all cities where Shinto is present. Of course, that would mean additional buildings, which means more work for someone! Ideally, I'd like an event(s) that can trigger after mountaineering that states the mountain has been climbed, which then gives additional . In the absence of that, additional on mountaineering would work.