Modern architects have long dreamed of building vertical forests. Now, growing urban density and the strain it puts on green space are pushing their vision forward, here and abroad.

Today, the development has 360,000 square meters, or 3.9 million square feet, of residential, office, retail and cultural space. Among them are the two towers of Bosco Verticale, or Vertical Forest, named for the hundreds of full-size trees to be planted on the buildings’ balconies.

The colossal columns are tiered up on four layers so that all the trees have enough space to grow upward. This composition of trees enables people everywhere in the building to enjoy urban views through the leaves of trees, in contrast to stark interiors of generic office space. The green giant order creates the facade like a vertical forest.

The 'CO2 Scraper' is a giant skyscraper that is essentially a vertical forest. It can hold 200-400 large trees, which naturally absorb carbon dioxide and convert it into oxygen.