There are the ruins of a Vihara to the right adjoining the Alms Hall and situated on higher ground. This is called Dage in Sinhalese meaning a relic house.
The inscription of King Mahinda IV belonging to the tenth century is installed on the two sides of the entrance to this Vihara.
The relic house is a square building.
It is quite possible that this relic house had an upper storey as well. If that was so, it is quite reasonable to believe that the upper storey was a wooden structure and decayed with the passing of time. However, some of the stone columns have remained intact so far.
The ground floor may have been put to use as an image house and the upper storey for the safe keeping of the Buddha relics. The domical shaped small Stupas on the four sides of the relic house bring glamour to this place.
It is also quite evident from the inscription of King Mahinda that this relic house had enjoyed a certain prestige in the tenth century.
The inscription in two parts to be seen on the two sides of the relic house was by King Siri Sangboy Abahay, now identified as Mahinda IV who ruled the country from 956 to 972 A.D.
The first part of the inscription sets with rules and regulations of the monastery, the contents of which are similar to those in the Jetavanarama Sanskrit inscription. The second part deals with the emoluments of the servants.
It is quite clear from this part of the inscription that no service whatever was accepted without paying for it either in money or in the form of grants of land or foodstuff.
Like many of the old stupas this too collapsed and was covered by the jungle. It was cleared and the debris removed during the early part of 1951 when the Archaeological Department took charge of the excavations. The terrace on which the Stupa stood was on ground raised about 10 feet above ground level. The diameter of the stupa is 88 feet.
Excavations into the heart of the mould revealed that vandals of earlier periods had ransacked this monument. These treasure hunters had robbed the dagaba of the objects contained in it and also destroyed works of ancient art. The vandals have only left a rosette of gold foil.
The walls of the chambers or Dhatu-garbha were covered with paintings but these have been destroyed owing to the chamber being exposed to the elements after the refilling of the Stupa. The sides have fallen down and of the numerous life size, painted figures which adorned the walls of the chamber, only the portions below the knee are now visible. Remains of 28 figures were clearly recognizable.
Clearing the pit dug by the treasure hunters, a stone slab with the lower chamber at a depth of about 8 feet from the upper floor was discovered. In the centre of the chamber was a Mahameru stone. A slab with three circular holes was also found. Cylindrical pieces of stone found in the debris fit into the holes.
It is therefore, evident that the model Mahameru in this chamber rested on three props just as the mythical Mahameru is believed to rest on three peaks called Trikuta. The walls were painted. The paintings depict divine beings among clouds.
The figures have been sketched in outline only, red and black being the pigments used, but are of high artistic quality indicating that the artist possessed skill in draughtsmanship a suitable sense of form and an understanding of the principle of balanced composition.
The relic chamber was in the centre of the dome of a Stupa, on the level of the top of the basal terrace or of the uppermost of the basal terrace of the Stupa which had three of these adjuncts. In some large Stupas a relic chamber was found at ground level and another below that too.
That at the ground level symbolized the earth, the one above it the heavenly world and that below ground the subterranean world of the serpents. The Stupa therefore, symbolized the Cosmos. The middle chamber with their paintings can be seen at the Archaeological Museum at Mihintale.
The flight of steps leads from the terrace of the Assembly Hall to the Ambastala plateau. Each step is about 28 feet long. The height is 6 inches. The width is 11 inches. At Ambastala or the plain of the mango trees is the living quarters of the residing Bhikkhus at Mihintale today.
In one corner is a Stupa with stone pillars. On the right hand side is an old Bodhi tree. The rock beyond that point is called the Aradhana gala or the invitation rock.
Mahinda Mahathera is supposed to have addressed King Devanampiyatissa from the top of this rock. On the rock that is to your south is the great Stupa or the Maha Saya and the adjoining Mihindu Saya. source : www.lakehouse.lk