Church of the Nativity at Bethlehem
The Church of the Nativity in Bethlehem, one of the four churches that Constantine built in Palestine, combined a basilica plan with an octagonal commemorative plan. A raised octagonal platform, or ambulatorium (walkway), was built over the traditional Cave of the Nativity. Two stairways (probably one for approach and one for departure) gave access to the platform, which included a balustrade around the opening to the cave. Pilgrims could climb the platform and look into the cave. An oculus (eye), an opening in the roof of the octagonal building, aligned directly above the cave, thus allowing light into the octagon. (See isometric drawing.) Although this design accommodated the pilgrims well, the lack of space for an altar and chancel must have made it difficult to hold religious services.