The chambers, which seem to follow no definite plan, are excavated in
the soft limestone and arranged in two storeys connected by a staircase,
part of which still remains in place. The finest rooms are in the upper
storey. The largest is circular, and contains in its walls a series of
false doors and windows. It is in this room that the remarkable nature
of the work in the hypogeum is most apparent. On entering it one sees at
once that the intention of the original excavator was to produce in
solid rock underground a copy of a megalithic structure above ground.
Thus the walls curve slightly inwards towards the top as do those of the
apses of Mnaidra and Hagiar Kim, and the ceiling is cut to represent a
roof of great blocks laid across from wall to wall with a space left
open in the centre where the width would be too great for the length of
the stones. The treatment of the doors and windows recalls at once that
of the temples above ground. The mason was not content, when he needed a
door, to cut a rectangular opening in the rock; he must represent in
high relief the monolithic side-posts and lintel which were the great
features of the megalithic 'temples' of Malta. Nor has he failed in his
intention, for, as one moves from room to room in the hypogeum, one
certainly has the feeling of being in a building constructed of separate
blocks and not merely cut in the solid rock. No description can do
justice to the grace of the curves and the flow of the line in the
circular chamber and in the passage beyond it, and we have here the
work of an architect who felt the æsthetic effect of every line he
traced.

Behind the circular chamber and across the passage just referred to lies
a small room which, rightly or wrongly, has been called the 'Holy of
Holies,' the idea being that it formed a kind of inner sanctuary to the
chamber. It contains a rough shelf cut in the wall, and in the centre of
this a shallow circular pit. It has been suggested that this pit was