In the modern urban landscape, two things come at a premium: a place for flora to flourish, and space for advertising. A German company has approached the issue of cleaning our cities’ air with a unique and multipurpose solution. Their creation, called the “city tree” is a freestanding, self-sustaining structure, which uses moss as a substrate to feed plants arranged using a weighted system. It has its own irrigation system that uses captured rain water and a series of sensors to keep everything growing. The artful display of the plants themselves is what contributes to the visual appeal, as well as providing companies a more sustainable place to advertise that is more aesthetically pleasing than big bill boards that pollute the skies. Read more and see photos here.