One of the most striking sights in sumo is the giant roof suspended over the ring.
The 6.5-metric-ton structure is modeled on the roofs of Shinto shrines and held in place by 2.2-cm thick wires that can bear almost five times as much weight — meaning there is little danger of it falling.
From the mid 1700s, when the roof was introduced, it was supported by pillars in the four corners, but when sumo started being televised in the 1950s those were removed to improve the viewing experience.