The control room of an airport control tower is octagonal and has windows at at least two ends of the room, and work stations for controllers adjacent these windows. Each of the two windows extends along three adjoining sides of the room, and the work station is disposed behind the window at the middle of the three sides. The controller at each work station has a lateral field of view of at least 180.degree. unobstructed by mullions or other structural supporting elements. The windows are composed of planar transparent panels, and sealing elements which pose no significant obstruction to vision are provided at the joints between the panels.