The Jewish ritual immersion pool used for conversion and purification is called a mikveh.
A mikveh is a facility containing water used for ritual immersion under Jewish law. Its water must meet specific requirements, traditionally involving naturally gathered water such as rainwater or a spring, with detailed legal rules governing the pool’s construction and connection to the water source.
Conversion candidates traditionally immerse in a mikveh as part of entering Judaism. The pool is also used in several family-purity practices and in some communities before holidays or other significant religious occasions. Men and women may use mikvaot, depending on the practice and purpose.
A mikveh is not simply a swimming pool or a bathhouse. The immersion is a religious act carried out according to particular procedures, often with witnesses or guidance where Jewish law requires them. The plural form is mikvaot, although “mikveh” is widely used in English for both the institution and the pool.