In the south east of the chapel there is a chair which was reputed to be a seat that was sat in by Saint Helena, the mother of the Emperor Constantine when she was looking for the True Cross. There are two apses in the church, one dedicated to Saint Helena and one to the penitent thief on the cross. The chapel is modestly adorned in memory of Saint Helena's simplicity.
The chronicler William of Tyre reports on the renovation of the Church of the Holy Sepulcher in the mid-12th century. The crusaders investigated the eastern ruins on the site, occasionally excavating through the rubble, and while attempting to reach the cistern where the True Cross was believed to have been found, they discovered part of the original ground level of Hadrian's temple enclosure; they decided to transform this space into a chapel dedicated to Helena, widening their original excavation tunnel into a proper staircase.
During 1973–1978 restoration works and excavations were made on the Holy Sepulchre To the east of the Chapel of St. Helena, the excavators discovered a void containing a 2nd-century drawing of a roman ship, two low walls which supported the platform of Hadrian's 2nd-century temple, and a higher 4th century wall built to support Constantine's basilica; the Armenian authorities have recently converted this archaeological space into the Chapel of Saint Vartan, and created an artificial walkway over the quarry on the north of the chapel, so that the new Chapel could be accessed (by permission) from the Chapel of St. Helena.