Dohyō
A dohyō (土俵, Japanese pronunciation: [doçoː]) is the space in which a sumo wrestling bout occurs. A typical dohyō is a circle 4.55 m (15 ft) in diameter, bounded by partially buried rice-straw bales. In official professional tournaments (honbasho), it is mounted on a square platform of clay 66 cm (26 in) high and 6.7 m (22 ft) wide on each side.