2. Spain's bubble-shaped freshwater factory

Spain's bubble-shaped freshwater factory [CRIOnline.com]

This freshwater factory is comprised of a series of biospheres stacked on top of each other. From outside, it looks like soap bubbles. The glass domes of this eccentric tower play a vital role: filtering seawater into freshwater through mangrove trees, which draw in saltwater and perspire freshwater.

Once the mangroves release this precious substance, it evaporates and condenses into dew which collects in freshwater tanks.