The nation of Peru is undergoing a building boom, which is obviously great for the economy. But in the capital, Lima, which already has an air-quality problem, all that construction is also adding yet more pollution to the humid air of the South American city.
UTEC, an engineering school in the city, decided to do something about the problem when it announced plans to expand its campus. The school has constructed a billboard that also serves as a giant air purifier, absorbing the particles and soot kicked up by the construction and filtering them out. The giant sign helps keep the air pure for several square blocks around the campus and is believed to have the effect of about 1,200 trees. Check out the video above for more.