The local Sthala purana contains a mythical account of the foundation of the Temple which relates to the well-known story of the demon King Hiranya-Kasyapa and his son Prahlada. Hiranyakasipu and Hiranyaksha who are brothers and mighty demon lords bent upon disturbing the peace of the world.
Hiranyaksha, seized the earth and carried it to neither regions. Lord Vishnu killed him and delivered the earth from the clutches of the demon by assuming the Boar incarnation (Varaha Avatara). Hiranyakasipu wanted to avenge the death of his brother Hiranyaksha. He wanted to become immortal and hence performed austerities (tapasya) to propitiate Lord Brahma. However, Lord Brahma said that was not possible so Hiranyakasipu asked Lord Brahma to grant him a boon so that he could not be killed by either animal or a man neither in the morning nor in the night, by any weapons, neither in sky nor on the earth. Hiranyakasipu wanted the entire world to worship him. He added to his might the power of penance and began to punish the gods and sages, the devotees of Lord Vishnu.
Son of Hiranyakasipu, named Prahalada became a devotee of Vishnu even from his birth and thus brought upon himself the wrath of his father. Hiranyakasipu tried to mend the ways of his son, but when he found him to be adamant, made him undergo severe hardships. He made the elephants trample over him and set poisonous snakes against him. Prahalada, protected as he was by divine grace, stood firm Hiranyakasipu as a last resort, asked his servants to throw his son into the sea and place huge mountain over him. His servant choose to drop Prahalada in the sea near the mount Simhadri with a view to place the mountain over him. But before they could complete their act Lord Narayana rescued him by jumping over the hill and lifting up Prahalada from the sea. Simhadri is thus the place where the Lord rescued Prahalada.
The form of Varahanarasimha (Dwayavathara) was assumed by him, on the prayer of his devotee, Prahalada, who wanted to see both the incarnations of the Lord, the one by which he had already killed Hiranyakasha and the other by which he would kill Hiranyakasipu.
According to Stalapurana, Prahalada was the first person to construct a temple round the Deity. He accomplished this after his father’s death at the hands of Narasimha. But at the end of that life-cycle (Krita yuga), the temple was neglected and began to decay. Even the Deity was not taken care of and crests of earth slowly gathered round the image.
But, at the beginning of another life-cycle, the Lord once again was discovered by Emperor Pururava of the Lunar Dynasty. Pururava, with his spouse Urvasi, riding on an aerial chariot over the hills of the South, was drawn to Simhachalam by a mysterious power. He discovered the Lord on the hill lying imbedded in crests of earth. He cleared the earth around the image of the Lord. Then he was addressed by the akaasavani not to expose the image but cover it with sandal paste. It also added that the Lord should be worshipped in this form, and only once in a year, on the third day in the month of Vaisakha his nijaswarupa can be revealed. Acting under the instructions of akaasavani, king pururava applied over the image an amount of sandalwood paste which is equal to the mud he had removed, worshipped the deity, and built the temple once again around the image. The temple continued to flourish ever since.