Annesley Street Synagogue has the archaeological remains of a Mikvah, a ritual bath. The Mikvah is central to orthodox Jewish communities. Often, when a new Jewish community was formed the Mikvah would be built before the Synagogue. 

Traditionally, Jewish men and women would regularly immerse themselves in water to achieve spiritual cleansing. The name Mikvah comes from the Hebrew word for ‘collection’, as in a collection of water. There are two requirements for these ritual baths. Firstly, that they are large enough to fully immerse the human body. Secondly, that the water stems from a natural source i.e. is connected to a natural spring or a well of collected rainwater.

The idea of a Mikvah is that there is no barrier between the person and the water. This means that, before immersing in the Mikvah, Jews must ensure that their body is thoroughly clean. Preparation typically includes taking a bath or shower, clipping nails, and brushing teeth.  For women, this also includes removing jewellery, nail varnish, make up and any beauty products on the hair or skin to ensure there are no barriers between the person using the bath and the Mikvah water. Correct immersion in the Mikvah requires the entire body and every strand of hair to be fully underwater.

The Mikvah is used by both men and women but the reasons for immersion vary according to gender:

• Women are required women to immerse before getting married and when observing the laws of niddah (menstrual purity). Traditionally, immersion in the Mikvah is seen to take the woman from a state of impurity (or ‘tumah’ in Hebrew) to a state of purity (‘taharah’). Tumah and taharah, however, do not correlate with clean and dirty but instead represent the immersion of the soul.
• Observant men may use a Mikvah before Shabbat (the Jewish Sabbath) and before Jewish holidays like Yom Kippur (the Day of Atonement). Some grooms will also visit the Mikvah before their weddings.
• For all genders, a dip in the Mikvah constitutes part of the process of conversion to Judaism. The ritual bath may also be used to help prepare a body for burial.

More recently, the Mikvah has enjoyed a revival among less observant Jews, many of whom view it as a way to mark transitions in their lives. ‘Open’ Mikvahs are those that welcome Jews for reasons not required by Jewish law and these baths encourage people to immerse themselves after significant life events. These may include a divorce, finishing chemotherapy, a graduation or to find closure after trauma or loss.