This idol, called the Mulaberam, is believed to be self-manifested. As there is no known sculptor possessing the capability to sculpt idols of god so proportionately. Further, no human being is known to have installed it in the shrine.The idol of the Lord wears a gold crown (Kiritam), which has a large emerald embedded on its front. On special occasions, it is replaced with a diamond kiritam. On the forehead of the idol, two thick patchs of tilak drawn with refined camphor, almost covers the eyes of the idol. In between the two white patches is a Kasturitilakam.
Golden makara kundalas hang to the ears of the idol. The palm of its raised right hand is embedded with a gem-set Sudershana Chakra, and the left palm with the Holy Cone. The slightly outstretched front right hand, has its fingers pointing toward the feet, as if Lord is the only recourse to his devotees to dissolve in him and enjoy eternal bliss. The akimbo of the front left hand implies lord's protection to devotees, and to show that the Samsara Sagara (Ocean of Life) is never deeper than to hip's height, if they seek his refuge.
The body of the Idol is spun with a Gold-stringed-Pitambaram, with a belt of golden-bells. The idol is decorated with precious ornaments. It has a sacred thread flowing down, cross from the left shoulder. It bears Goddess Lakshmi on the right chest and Sri Padmavathi Devi on the left. Nagaabharanam ornaments are on both of the idol's shoulders.The lotus feet are covered with gold frames and decked with clinging gold anklets. A strong curved belt of gold encompasses the legs. During Abhishekam, we can have darshan of Goddess Lakshmi.
The Ananda Nilaya Divya Vimana was covered with gilt copper plates and covered with a golden vase, in the thirteenth century, during the reign of the Vijayanagara king, Yadava Raya.
Pilgrims are not allowed to enter the Garbha Gruha (beyond Kulasekhara padi (path)).