What is "judan"

Judan can refer to:

• Judan, Iran, a village in Markazi Province, Iran
• Judan, Isfahan, a village in Isfahan Province, Iran
• The 10th degree black belt in Dan rank in Japan
• Judan (Go), a Go competition in Japan
• A shogi competition in Japan between 1962 and 1987; see Ryu-oh

The Judan (十段)—which can be translated as "10 dan"—is a Go competition in Japan. It is one of the seven major professional titles.