A Hyperboloid style tower,

Belgium.

The cooling tower is a hyperboloid style tower, they have become the design standard for all natural-draft cooling towers because of their structural strength and minimum usage of material, the hyperbolic shape of the tower enhances aerodynamic lift due to the wind passing over it which increases the air flow rate. The air flows into the openings in the bottom which rises up and cools the entering hot water. The cooled water cascades down to the bottom of the tower whilst the warm moist air exits out of the top. In its hey day this tower would have been able to cool up to 480,000 gallons of water a minute.