Skeptics of improbably green skyscraper concepts might want to take a moment of silence to appreciate the successful construction of these two beautiful buildings now nearly completion.

Designed by Stefano Boeri in Milan, Italy, the twin towers of the Bosco Verticale play host to nearly 1,000 trees, 5,000 shrubs and over 10,000 additional small plants.

The building was fully designed with its greenery in mind, including accommodations for irrigation, root systems, plant weights and wind loads within the city. This rich miniature ecosystem of plant life in turn helps filter the surrounding air, dampen urban noise and provide shade for residents. For its local environment, the building increases biodiversity and provides habitats for regional birds and insects.

From the designers: “The creation of a number of vertical forests in the city will be able to create a network of environmental corridors which will give life to the main parks in the city, bringing the green space of avenues and gardens and connecting various spaces of spontaneous vegetation growth. [This project] helps to build a micro-climate and to filter dust particles which are present in the urban environment. The diversity of the plants helps to create humidity, and absorb CO2 and dust, produces oxygen, protects people and houses from the suns rays and from acoustic pollution.”

Concept designs from far-fetched futurists have toyed with the idea for years, but one firm has finally made the vision a reality: towers extensively populated with intensive (meaning: large and heavy) plant life. In short: trees!

Situated in Milan, Italy, many skeptics were sure these two towers were just another pie-in-the-sky plan for an impossible building. After all, the load-bearing requirements alone for over 10,000 trees and 5,000 shrubs are extreme. Stefano Boeri Architetti (photos by Marco Garofalo) is showing them otherwise.

The added weight is not wasted, nor ornamental – the vegetation layers will reduce the need for temperature regulation within the building. They will also filter the congested air of the city and serve to help reduce the temperature (always higher in urban areas).

The pre-grown plant life was carefully selected for the structure based on the regional climate, light and wind exposure, and is even now being hoisted into final positions. When complete, this will be, on some metrics, quite literally the greenest pair of buildings in the world.