Spanish architecture firm Selgas Cano recently unveiled their new office in Madrid. Located within a forest, the tube-like structure is half-sunken into the ground, giving the illusion of complete isolation. A large window runs the entire length of the structure and forms part of the roof, ensuring workers a panoramic view of the surrounding woods. The office is entered via a partially-hidden stairwell and has retractible shutters at the end of the structure. Selgas Cano’s design is seen here photographed by world-renowned dutch architecture photographer Iwan Baan.