Designed in Beijing by Rem Koolhaas and OMA, the CCTV (China Central Television) Headquarters rejects the skyscraper cliché of "a single vertical tower tapering as it rises" and proposes instead a closed loop.

The building is made of two inward-leaning towers. These rise from a common base at the ground and join at the top, at 75 metres' height, by a giant cantilevered bridge reaching out into the void. The result is a continuous structural loop whose head and foot meet — not a vertical tower but a standing closed loop. This form generates extraordinary forces: the leaning towers and the overhanging corner subject the structure to constant torsion and unbalanced loads.

The solution is the irregular diagonal steel mesh (diagrid) visible on the facade. The pattern of this mesh is not decorative: the diagonals grow denser where stress concentrates and sparser where the load is light. The facade pattern is thus directly a map of the flow of forces — it lets the eye read where and how much the structure is strained. The CCTV thus sets up an alternative to the vertical tower in supertall building: a closed-loop typology that circulates the load along a loop and displays the stress on its surface.