The erection of a royal residence on a platform composed of several terraces involved the necessity of artificial ascents, which the Persian architects managed by means of broad and solid staircases.  These staircases constitute one of the most remarkable features of the place, and seem to deserve careful and exact description. [PLATE XLI., Fig. 2.]

[Illustration:  PLATE XLI.]

The first, and grandest in respect of scale, is on the west front of the platform towards its northern end, and leads up from the plain to the summit of the northern terrace, furnishing the only means by which the platform can even now be ascended.  It consists of two distinct sets of steps, each composed of two flights, with a broad landing-place between them, the steps themselves running at right angles to the platform wall, and the two lower flights diverging, while the two upper ones converge to a common landing-place on the top.  The slope of the stairs is so gentle that, though each step has a convenient width, the height of a step is in no case more than from three to four inches.  It is thus easy to ride horses both up and down the staircase, and travellers are constantly in the habit of ascending and descending it in this way.

The width of the staircase is twenty-two feet—­space sufficient to allow of ten horsemen ascending each flight of steps abreast.  Altogether this ascent, which is on a plan unknown elsewhere, is pronounced to be the noblest example of a flight of stairs to be found in any part of the world.  It does not project beyond the line of the platform whereto it leads, but is, as it were, taken out of it. [PLATE XLII.]

[[Illustration:  PLATE XLII.]

The next, and in some respects the most remarkable of all the staircases, conducts from the level of the northern platform to that of the central or upper terrace.  This staircase fronts northward, and opens on the view as soon as the first staircase (A on the plan) has been ascended, lying to the right of the spectator at the distance of about fifty or sixty yards.  It consists of four single flights of steps, two of which are central, facing one another, and leading to a projecting landing-place (B), about twenty feet in width; while the two others are on either side of the central flights, distant from them about twenty-one yards.  The entire length of this staircase is 212 feet; its greatest projection in front of the line of the terrace whereon it abuts, is thirty-six feet.  The steps, which are sixteen feet wide, rise in the same gentle way as those of the lower or platform staircase.  The height of each is under four inches; and thus there are thirty-one steps in an ascent of ten feet.