The city of Madrid soon plans to add a striking new structure -Air Tree pavilion- that will “climatically transform” its urban architecture. It also produces oxygen like a tree, hence the name. The Air Tree pavilion is to be built from recycled materials and will be 100% energy self-sufficient. Using photovoltaic cells, the Air Tree produces a substantial amount of energy, which is then sold back to the local electric companies, and, of course oxygen - hence the name Air Tree. It's a completely unique idea and one that, unlike most out-of-the-box ideas, is actually being made a reality.