The raised ring for professional sumo bouts is traditionally built from clay.
The dohyo is a platform made from packed earth or clay, with a circular contest area on top. Its surface must provide enough firmness for stable footing while allowing wrestlers to push, pivot, and attempt throws. The ring is rebuilt or carefully prepared for official tournaments according to established practice.
The circular boundary is marked by rice-straw bales embedded in the clay. The surface is covered with fine sand, which helps officials see marks made when a wrestler’s foot or hand touches down. The raised platform also makes the action visible to spectators.
The clay dohyo is different from modern wrestling rings, which usually use spring floors and ropes. Professional sumo has no ropes around the contest area; crossing the straw boundary or touching the clay outside it can decide the bout.