Here beside the main Buddhist temple, is an exclusive shrine for Vibhishana. This site has been identified as the site of the ancient palace of Vibhishana, who was the younger brother of Ravana.
During the legendary war on Lanka, Vibhishana became a supporter of Lord Rama, because he disapproved of Ravana's abduction of Sita. After Ravana's death
Rama appointed Vibhishana as the new King of Lanka. Vibhishana is venerated by Sinhalese Buddhists as a God, they believe him to be one of the main protectors of the island, especially in its western territories.
Here you can find a rock cut sculptured panel, depicting the coronation of Vibhishana. Lakshmana is depicted here in this panel to be conducting the coronation of Vibhishana which is in line with the description of this event in the Ramayana. Rama, who was still undergoing his 14 years of Vanavasa, exile in the forest, did not enter the city to conduct the coronation, but instead, it is said that he had deputed Lakshmana to do so on his behalf.
In the coronation sculpture, the queen of Lanka sitting beside Vibhishana is identified by some observers, as Mandodari. However, it should be noted that, Mandodari did not occupy the throne of Lanka with Vibhishana. After Ravana’s death, Mandodari had instead gone into mourning. Vibhishana was a married man, whose wife was known as Sarama and he also had a daughter called Trijata, who earlier had been deputed to attend to Sita’s needs, when Sita was held captive by Ravana at Ashoka Vatika. So it's most likely that it is Vibhishana’s wife, Trijata’s mother who had occupied the throne along with Vibhishana at the time of the coronation and not Mandodari.
Even to this day, locals come here to pray to Vibhishana for quick and favourable settlement of disputes. The fact that it has been a local custom, to come here to pray for settlement of disputes, and not for the fulfillment of any other desires, shows the regard the locals have, for continuing a tradition, of treating this place as a King’s court. This continuing custom has lasted for thousands of years, and also goes to show the great kingship qualities of Vibhishana and the high esteem in which he was held by the local population of Lanka.
When the Portuguese destroyed the ancient Viharaya in 1575, all the sculptural work and paintings, perished with it, so the paintings and works of sculpture you find here today are of the 18th to the 20th century. The old paintings were done when the temple was rebuilt in the Kandyan period. They decorated the walls and ceilings of the two chambers of the old wing. In these old paintings we could clearly notice South Indian influence on Sinhala art.
It should also be noted that this monument is located on the banks of Kelani Ganga, one of the most important and perennial rivers of Sri Lanka. The root of the word Kelaniya come from the Sanskrit, Pali word Kalyani, which means auspicious.