This is the staircase of the hotel, under is jet black, It is an artificial basin actually, It looks like has the return natural flavor.

这是酒店大厅的楼梯…下面黑洞洞的，其实是一个人工水池，看起来有回归自然的味道。

youdao

Surface water-mostly rivers, lakes and reservoirs-will not flow from one basin into another without artificial diversion, and usually only with pumping.

包括主要由河流、湖泊、和水库组成的地表水必须要通过人工引流才能从一个盆地进入另一个盆地，很多时候能够依赖的技术只有水泵。

youdao