下雨時 因為中間突起 所以水會順著地勢排開
If we mention Europe history, we have to talk about Greece history and Parthenon.
Parthenon temple is very interesting.
It looks like building in a plain, but actually not. The land in the middle is higher than around. So Ancient Greek was very intelligent, they do very good job, let this building looks like all the same level! Not only this, because the land is not the same level, if rain, the water will go down not in the middle. I have to say they were really nice!!!