The lower half is thus a solid, almost perfectly cubical monolithic block, about square by high, surrounded on three sides by passageways which separate it from the vertically-cut rock of the Mount of Olives. It is decorated from the outside on each side by pairs of Ionic half-columns, flanked in the corners by quarter-columns and pillars (a so-called distyle in antis arrangement). The four square facades are crowned by a Doric frieze of triglyphs and metopes and an Egyptian cornice.