Sigiriya rock is the hardened magma plug from an extinct and long-eroded volcano. It stands high above the surrounding plain, visible for miles in all directions. The rock rests on a steep mound that rises abruptly from the flat plain surrounding it. The rock itself rises 370m and is sheer on all sides, in many places overhanging the base. It is elliptical in plan and has a flat top that slopes gradually along the long axis of the ellipse. Sigiriya consists of an ancient castle built by King Kasyapa during the 5th century AD. The Sigiriya site has the remains of an upper palace sited on the flat top of the rock, a mid-level terrace that includes the Lion Gate and the mirror wall with its frescoes, the lower palace that clings to the slopes below the rock, and the moats, walls and gardens that extend for some hundreds of metres out from the base of the rock. The site is both a palace and fortress. Sufficient remains to provide the visitor with a stunning insight into the ingenuity and creativity of its builders. The upper palace on the top of the rock includes cisterns cut into the rock that still retain water. The moats and walls that surround the lower palace are still exquisitely beautiful.  Site plan The Sigiriya Rock seen from the Gardens The Sigiriya Rock seen from the Gardens Sigiriya is considered as one of the most important sites of urban planning of the first millennium, the site plan is considered very elaborate and imaginative. The planning had combined concepts of symmetry and asymmetry to intentionally interlock the geometrical plan and the natural form of the surroundings. The west side of the rock lies a park for the royals which is symmetrically planned, the park contains water retaining structures which includeds sophisticated sub/surface hydraulic systems of which some are working even today. The south contains a man made reservoir, these were extensively used from previous capital of the dry zone of Sri Lanka. Five gates were placed at entrances. The more elaborate western gate is thought to be reserved for the royals.