If there are any employees who sit hunched over computers for many hours each day, it has to be those who work for Facebook. The Menlo Park, California-based headquarters installed a 9-acre green roof filled with a plethora of native trees and flowers, lawn furniture, white boards, viewing decks, more than 400 trees and a half-mile walking trail overlooking the city’s marshland, as an escape.

Described as more of a park than a green roof, the space is large enough to accommodate a nice group of the company’s 2,800 employees. In fact, the space is the size of seven football fields.

The goal was to create an environment where employees could think, meet and be inspired with new ideas. So far, employees are using the space to work on laptops in an open-air space, scribble notes on the white board or take timeouts to clear their heads.

And, of course, the roof does more than create an employee refuge. It absorbs heat and rainfall, helping the company cut down on energy use and stormwater runoff. Considering California’s current drought, the plants are all able to survive dry weather.

Future plans for the roof include adding eating areas and a sandwich shop staffed by company chefs.

Editor’s note: This article was originally published in July 2015 and has been updated.