I guess this doesn't qualify as a third weird thing about the lake rather than a subset of the previous oddity, but they also farm on the lake. As you can see, they again put stakes in the lake, and cover the top with straw and soil, then grow all sorts of vegetables on these floating gardens. I guess here I can see an advantage, in that the crops would be easily watered, but again, it's a lot of additional work over the usual land based agriculture.