The baptistry may be located within the main structure of a [[church]] or as a separate structure located adjacent the church. Commonly, the sacrament of baptism for those becoming Orthodox Christians is conducted in the [[nave]] of the church, generally in portable pools or fonts[[font]]s. In some churches the font or baptismal pool maybe "built-in". Baptisteries were found in many early churches in Asia Minor and Italy. A sixth century example can be found in the Great Church of Holy Wisdom ([[Hagia Sophia (Constantinople)|Hagia Sophia]]) in present day Istanbul.