Plunge pool or waterfall lake is a deep depression in the stream bed at the base of the waterfall. It is created by the erosional force of the cascading water. They occur at the youthful stage of the river development.
The South China Sea is a marginal sea of the Western Pacific Ocean. It is the biggest sea by size. It is bounded in the north by the shores of South China, in the west by the Indochinese Peninsula, in the east by the islands of Taiwan.