In Peru, it hardly ever rains and most water sources are polluted, but the humid air is full of water vapor. So the University of Engineering and Technology has rigged up a billboard to suck drinking water out of thin air.

Taking advantage of capital city Lima’s high humidity levels, engineers have created a system to gather the water through reverse osmosis, purify it, and send it down, clean, to families below.

It’s already produced almost 2,500 gallons of water and is the only billboard we’ve ever seen that actually can justify its existence.