Those aren't just towers—they're enormous,Secret Sex Society (2018) verdant air filters for smog-choked cities.

Vertical Forests blanket buildings with trees and plants, to soak up urban air pollution, produce clean oxygen, and boost local biodiversity. Now China—a nation grappling with dangerous smog from coal plants, factories, and vehicles—will get green buildings of its own.

This week, Italian architecture firm Stefano Boeri Architetti unveiled its designs for the Nanjing Green Towers, a pair of multi-use buildings planned for the Pukou District of Nanjing, the capital of China's southern Jiangsu province.

The Vertical Forests together will feature 1,100 trees from nearly two-dozen local species, as well as 2,500 cascading plants and shrubs. The green area will span a combined 6,000 square meters, or about 64,600 square feet.

The manmade forests will absorb 25 tons of carbon dioxide annually and produce about 60 kilograms of oxygen every day, according to the architects.

Boeri's firm said it expected the green tower project would be completed in 2018. The team is also eyeing future projects in other major Chinese cities, including Shijiazhuang, Liuzhou, Guizhou, Shanghai and Chongqing.

In Nanjing, the towers will follow the prototypes of Boering's original Vertical Forest in Milan, Italy, and a second project in Lausanne, Switzerland.

These Vertical Forests are far from the only projects to combine outdoor greenery with concrete and glass.

Mexico City's Via Verde Project, for instance, is transforming highway pillars into gardens to help cleanse the air, beautify the urban environment and lower drivers' stress levels.

In China, the tallest Nanjing Green Tower will soar 656 feet high and feature offices, a museum, a green architecture school, and a private rooftop club. The shorter tower, a 354-foot-high building, will include a Hyatt hotel and a rooftop swimming pool.

Both buildings will rest on a 66-foot-high podium that will host a food market, restaurants, a shopping center and a conference hall, the architects said.

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