Landforms and water
Shui Kou (water gate)
Where water enters and leaves the view — the tighter the exit, the better.

The water gate is the mouth through which water around a site comes into and passes out of view. When the outgoing side is narrowed by hills or woods so the water is not seen draining straight away, qi and wealth are read as staying. An open frontage where the watercourse runs straight into the distance is read as dispersal.
Related landforms
Source: Standard form-school feng shui (Xingqi) — the landform tradition