Surrounded by greenery, the Atagoyama area of Minato-ku in Tokyo has always been loved as a famous lookout point, and is regarded as a valuable site for many historical and culturally important temples and shrines. Atago Green Hills was planned with the development philosophy of preserving the topography and greenery of the Atagoyama area while making use of this important inner city landscape resource. Centered on the rebuilding of the historical temples, the Mori Tower with consolidated office functions and the Forest Tower with consolidated residential functions were paired off together along a 38,450 square meter development area of Atagodori Avenue.

Open space was secured in the low-level sections of the two towers, the exteriors of which were designed by Cesar Pelli, creating an open and comfortable feeling. Exterior curtain walls give a unique three-dimensional flower bud-shape to the high-rise sections of the superhigh-rise Mori Tower structure, which rises 188 meters from the ground. The structure is a combination of CFT columns and oil dampers, and the building has a high-level security system, which is also installed with the latest communications infrastructure. In order to get around the problems associated with the peculiar design of the upper level sections, and to reduce the work period, various methods were developed such as a large steel unit upwards positioning and ground assembling method, a method for making exterior curtain walls into units, and a column-type crane for installation work. This enabled high quality and efficient work to be pursued.