The specific explanation is as follows
People usually say that Feng Shui is good when surrounded by mountains and rivers. This is because in Feng Shui, mountains manage people and water manages wealth. The family's survival and reproduction can be relied on, and the descendants can continue to grow; being near water means that this place has the luck brought by water, which can be very beneficial to the improvement of wealth. Therefore, if you can settle down in such a place, it will often be very beneficial to your fortune.
Feng Shui in a valley
Being close to a mountain does not mean that there are mountains next to it. If there are endless mountains next to it, and the site is located in the valley, between the two mountains , that would be bad. Living in such a place often leads to poor fortune and difficulty in getting ahead in career, especially because there is water in the valley, which causes serious dampness, which is quite detrimental to both wealth and health.