These twin residential towers are covered in 900 trees and 20,000 plants — a vertical forest in the middle of a major European city.

Designed by Stefano Boeri, Bosco Verticale (Vertical Forest) consists of two towers (116m and 76m). The vegetation absorbs CO2, produces oxygen, and reduces noise. It won the International Highrise Award in 2014 and has inspired similar projects worldwide.