Another name for a sangha hall (sōdō 僧堂). The name "cloud" (un 雲) "hall" (dō 堂) is sometimes explained as an abbreviation of "clouds and water hall" (unsui dō 雲水堂), because in Japanese Zen young monks in communal training at a monastery are called unsui and the sangha hall is where they are quartered. However, at the time when Dōgen was in China, the designation unsui 雲水 referred to wandering monks, who were likened to "fleeting clouds and floating water (kōun ryūsui 行雲流水) in their lack of any fixed abode. Those who had "hung up the staff" (kata 掛搭) of a wandering monk and taken up residence in a sangha hall were not called unsui, and the "clouds and water halls" (unsui dō 雲水堂) in Chinese monasteries were in fact temporary quarters for wandering monks who were not allowed into a sangha hall. The "cloud hall" seems to have gotten its name, rather, from the notion that the monks in a sangha hall are numerous and crowded together like so many clouds piled up in the sky.