The largest broadcasting tower (and second tallest manmade structure) in the world at 634 m (2080 ft), the Tokyo Skytree is was built because high-rises partially obscured the signals broadcast by the older Tokyo Tower.
The tower has seismic proofing, including a central shaft made of reinforced concrete. The main internal pillar is attached to the outer tower structure for the first 125 meters (410 ft) above ground. From there until 375 meters (1,230 ft) the pillar is attached to the tower frame with oil dampers, which act as cushions during an earthquake. Additional resilience is achieved through an "added mass control mechanism" (or tuned mass damper) – a damping system which, in the event of an earthquake, moves out of step with the building's structure, to keep the center of gravity as central as possible to the tower's base.