The basic meaning of the word gan in the context of East Asian Buddhist is "stupa," or more specifically, the space within a stupa where relics of the Buddha or an eminent monk are enshrined. By extension, gan came to refer to stupa-shaped coffins that are used in the funerals of monks and lay people, and to the stupa-shaped niches or alcoves that are used to enshrine a variety of Buddhist images (e.g bodhisattvas, ancestral teachers, devas). Because those images are the foci of prayers and offerings, the alcoves (gan 龕) that house them may aptly be called "altars." The Sacred Monk's altar (shōgan 聖龕) found in the sangha halls (sōdō 僧堂) and meditation halls (zendō 禪堂) of Zen monasteries is usually a roofed alcove that is enclosed on three sides and has a stupa-shaped opening in front. "stupa"