For the past eight years , Co.Design has been following the construction of Denmark’s much-awaited interactive power plant. Now, the 44,132-square-foot multipurpose destination—named CopenHill —is finally open to the public.

Designed by BIG (Bjarke Ingels Group), SLA, AKT, Lüchinger+Meyer, MOE, and Rambøll, CopenHill is a waste-to-energy plant crowned by an active ski slope, hiking trail, and climbing wall. The hybrid urban recreation center and environmental education hub is Denmark’s largest waste initiative ever and is part of Copenhagen’s pledge to become the world’s first carbon-neutral city by 2025.

“We are very proud to have built the most energy efficient waste-to-energy plant in the world,” Jacob Simonsen, managing director of ARC, said in a statement. “At the same time, the plant delivers the best environmental performance with hardly any environmental emissions, enabling us to have neighbors only 200 meters away and to be located less than 2km from the Queen’s Residence. Last but not least, we have succeeded in building the safest waste-to-energy plant, so local citizens and guests from all over the world can ski on the roof.”

This ambitious public infrastructure project boasts furnaces and turbines that convert 440,000 tons of waste into clean energy each year—enough to provide 150,000 homes with electricity and heating. All of this is held beneath the 107,639-square-foot green roof (which absorbs heat, removes air particles, and minimizes stormwater runoff). This biodiverse landscape doubles as a sporty architectural rooftop with 96,875 square feet of artificial ski terrain—the same length as an Olympic half-pipe. Visitors can reach this dynamic roof, which also includes slopes for beginning skiers and freestylers, by ascending on either a platter lift or a glass elevator—both of which run alongside the gilded, 24-hour plant within.

CopenHill’s nature roof park and hiking trail feature a mountainous landscape of plants, rockscapes, 7,000 bushes, and 300 pine and willow trees, Rasmus Astrup, partner and design principal at SLA, said in a statement.

“It also acts as a generous ‘green gift’ that will radically green-up the adjacent industrial area,” Astrup said. “CopenHill becomes the home for birds, bees, butterflies, and flowers, creating a vibrant green pocket and forming a completely new urban ecosystem for the city of Copenhagen.”

The building is vertically lined on its exterior with a 279-foot climbing wall—the tallest artificial one in the world. Within, there are also 10 administrative floors lit by wide, glazed windows, and a 6,458-square-foot education center for workshops and sustainability conferences. To descend from CopenHill’s summit, visitors will pass by a rooftop bar and fitness area as they travel down the 1,608-foot hiking and running trail, enveloped by terrain designed by Danish landscape architects SLA.