In the middle terrace to the south of the Assembly Hall is a low area. Here are found ruins of monastic buildings. Amidst them is found the attractive and artistic Lion Pond which is a unique sculptural piece.
Though it is called a pond, it is more a water rail than a pond. It is an open-air bath which was probably used by the Bhikkhus who were living in the caves of the neighbourhood.
It is called a pond because of the water tank above the figure of the standing lion from whose mouth the water comes out. Half of it is cut out of the natural rock and the other half is constructed of monolithic blocks to form a square pond. The rampant, life-sized lion is carved against the outer rock wall.
The water is discharged through the open mouth of the lion. The construction of the bath is described as follows by Bell: The live rock was first chiselled out by cutting back the sloping rock vertically, and at right angles, for a level width of 6 ft. 3 in. so as to form the south side of the bath.
Approximately six feet from the vertical rock at back was then marked off and within this squared space a depth of 1 ft. sunk in the rock perpendicularly, what remained was only to smooth the top of the rock on the sides to a splay and the front to a rough level, then to fit dressed monolithic slabs, cut to match, on three faces - and a cubicle bath was formed, half carved from the bed-rock, half of stone worked to shape and smoothed inside.
"Such construction" says Bell "would necessarily leave three sides of the bath rising more or less unprotected. To meet this want the architect strengthened and embellished his chef-d' oeuvre by supporting the structural slabs required to complete the rectangular bath with a moulded and ornamental platform based on the east, north and south faces."
The water for this open-air bath was supplied by a channel from the Naga-Pokuna situated just above the Sinha Pokuna on a higher elevation. The sculptures right round the pond depicting dancers, elephants, musicians and ganas etc. reveal the high standard that sculptural art had achieved in Sri Lanka at that time.