The Royal Bridge into Herod's Temple by Edersheim
Of the four principal entrances into the Temple--all of them from the west--the most northerly descended, perhaps by flights of steps, into the Lower City; while two others led into the suburb, or Parbar, as it is called. But by far the most magnificent avenue was that at the south-western angle of the Temple. Probably this was 'the ascent...into the house of the Lord,' which so astounded the Queen of Sheba (1 Kings 10:5) *
According to Mr. Lewin, however (Siege of Jerusalem, p. 270), this celebrated 'ascent' to the house of the Lord went up by a double subterranean passage, 250 feet long and 62 feet wide, by a flight of steps from the new palace of Solomon, afterwards occupied by the 'Royal Porch,' right into the inner court of the Temple.
It would, indeed, be difficult to exaggerate the splendour of this approach. A colossal bridge on arches spanned the intervening Valley of the Tyropoeon, connecting the ancient City of David with what is called the 'Royal Porch of the Temple.' From its ruins we can reconstruct this bridge. Each arch spanned 41 1/2 feet, and the spring-stones measured 24 feet in length by 6 in thickness. It is almost impossible to realise these proportions, except by a comparison with other buildings. A single stone 24 feet long! Yet these were by no means the largest in the masonry of the Temple. Both at the south-eastern and the south-western angles stones have been found measuring from 20 to 40 feet in length, and weighing above 100 tons.