At the east end of the nave is a semicircular passage or ambulatory which runs past the Chapel of Longinus and the Chapel of the Parting of the Raiment to a flight of steps leading down to St Helen's Chapel (Armenian). In the rock face on the right are small crosses incised by pilgrims of the Crusader period. The chapel is roughly square, with four short columns of the Byzantine period carrying the high arches of the roof structure. Through the dome light falls from above into the large central square, giving the chapel its own special atmosphere, which is enhanced by the lamps, the decorative fabrics and the altar. To the right of the principal apse is a recess from which Helen is said to have watched the bringing to light of the Roman cistern in which the True Cross was found.
