Leaving this chapel, and passing along the north aisle of the church, we find on the east, behind the Greek Church, a staircase leading down into the Chapel of S. Helena[430], belonging to the Armenians, the south side of which is partly formed by the rock. From the middle of it rises a dome, supported by four columns (of Egyptian granite) with Byzantine capitals[431], and surrounded by a terrace-roof occupied by the huts of the Abyssinians. Near the north-east corner of the chapel is a wooden altar, concealing a doorway, now built up; it communicated with a building called the Prince's House, which I shall presently notice. In the south-east corner is a kind of little balcony (erected by the Armenians in the 17th century), where, according to a false tradition, S. Helena stood while the workmen were seeking for the cross in the neighbouring cistern. This chapel was united to the main building by the Crusaders. In the south wall is a staircase, the steps of which are hewn out of the rock, though they are now covered up with stone slabs; it leads into a vault in which the Saviour's cross is believed to have been found, together with those of the two thieves, after lying hid there for 293 years. The legend is strongly supported by very ancient Eastern traditions. The interior, entirely excavated in the solid rock, corresponds in form with the cisterns so abundant in Jerusalem, and the holes still remain by which the water entered or was drawn out. The rock is a soft limestone, and differs from the fragment on the top of Golgotha; therefore I am inclined to believe that there is no connexion between the latter and this in the Chapel of the Invention of the Cross.