🇺🇸Glory Hole, Lake Berryessa.
A terrible whirlpool in the lake, absorbing everything that just gets into it.
A circular rotation is formed when encountering an obstacle, the water flow turns back, moving against the current. But all the water does not have time to return back and bumps into a newly arriving water flow. As a result, it begins to spin at a speed that largely depends on the speed of the main current.
https://goo.gl/maps/oHdB3k5ZrNR2r3Ne8