This temple is located in Nagalapuram 70 kms. south-east of Tirupati housing an image of the Matsya form of Vishnu, with Sridevi and Bhudevi on either side. It is believed that Lord Vishnu, in the form of Matsya, killed the rakshasa (demon) Somakudu here, retrieving the Vedas from the latter. A peculiar feature of the idol is that it holds the Sudarsana Chakra in prayoga (ready for release). Nagalapuram has the Vedanarayanaswamy temple built by Krishnadevaraya and his mother Nagamba.
Every year in March this town stirs into festivity for the Surya Puja when the rays of the sun fall on the deity's feet, navel and forehead at different times of the day, depicting worship by Sri Surya Bhagavan (the Sun God) himself. The sub-temples inside the main temple are: Sri Vedavalli Tayaru Sri Lakshmi Narasimha Swami temple Sri Veeranjaneya Swami temple Sri Bhakta Anjaneya Swami temple Sri Sita Lakshmana Sameta Ramulavari temple.
The most important annual festivals in this temple are Brahmotsavam, and Surya Puja along with the Float festival, conducted on the 12th, 13th and 14th days of the month of Phalguna.