People are much more creative when they're relaxed. It is expected that employees in architectural studio should be creative as much as possible, so Spanish Architect firm Selgas Cano designed its offices to have the natural atmosphere.
The offices are located in the forest near Madrid and when you are in it it feels liku you are in the park. It's quiet and peaceful so you can be creative more than in usual office.
The fact that the space is partly underground, so your head is in the ground level make you feel even more connected to the nature.