According to Sthalapurana, the world became a dark and a dangerous place when rakshasa disturbed and prevented Brahma from conducting yagna. The Lord appeared and brought light and life back to mankind and hence called Deepaprakasar (Vilakkoli Perumal).
Swami Nigamanta Desika's avathara sthala.
This place is about 2 kms from Kanchi Varadarajaswami temple.