St Mary & St Barlok's Church, Norbury (Piscina)

A double piscina set in the church wall to the side of the altar.
(I believe it was more usual to have only a single one and the double ones are quite a rarity?)
The Dictionary definition is: ‘A stone basin with a drain for carrying away the water used for Mass or for ceremonial ablutions’. Also called ”sacrarium”.

(Information provided by Peter & Janet Kirk)