How many Feng Shui Long Mai are there in the legend of China?

Do you think Long Mai is easy to find? You know, many emperors in ancient times did not live in Long Mai. Long Mai is also different, for example, what is disposable Long Mai, used ones can't be used, longan, dragon cave and so on. Legend has it that as long as the bones of the predecessors are thrown into the eyes of the dragon, the younger generation will certainly be promoted. There is also Longdong. I heard that the famous "hanging coffin" in Sichuan is Longdong. ! !