A short walk from Milan’s busy Garibaldi train station, a new library is springing up from the ground. But this library isn’t filled with books – it is a “Library of Trees”. Transforming the grey piazza in the heart of Milan’s Porta Nuova business district began with the planting of seeds in September, and will be followed by trees and plants in November.

In total there will be 450 trees from 19 species, plus 90,000 plants including hedges, shrubs and climbers. When complete next year, the Biblioteca degli Alberi will be a 3,500m2 green space in the heart of a city that is increasingly returning to nature. Overlooking the Biblioteca degli Alberi is Milan’s “Vertical Forest”: two residential tower blocks built in 2014 that are covered in 800 trees, 4,500 shrubs and 15,000 plants.