Thirukkannapuram, close to Nannilam, is famous for its Vishnu temple dedicated to Neelamegha Perumal, also known as Sowriraja Perumal. It is one of the one hundred and eight Divya Desams which are places sacred to Vishnu, eulogised in the Tamil verses of the Azhvars (famous devotees of Narayana). This deity has been praised by Nammazhvar, Kulasekhara Azhvar, Periyazhvar, Andal and Thirumangai Azhvar. This place is also known as Ashtakshara Mahamantra Siddhi Sthalam as it is said that the deity taught the Ashtakshara Mantra t o Thirumangai Azhvar here.
Perumal in this temple is believed to be the embodiment of the Ashtakshara Mantra. Thirukkannapuram is one of the five Krishnaranya Kshetrams, the others being Therezhundur, Thirukkannangudi, Thirukkannamangai and Kapisthalam. The principal deity (Moolavar) Neelamegha Perumal, is in a standing pose, facing East, holding the Sankha (conch) and Chakra (discus) in the upper hands. The Chakra is in the prayoga mode, with the rim facing outward, as though about to be hurled at enemies. The Moolavar is enshrined along with Goddesses Sridevi, Bhudevi, Padmini and Andal. The processional image (Utsava- murti) is known as Sowriraja Perumal.
Intererstingly, thirumanjanam (abhisekam) to this processional deity is performed only once a year, while on other days, only the feet of this image are washed. One of the inscriptions in this temple mentions his name as Savurip-Perumal and as Azhvar Savurip-Perumal. These deities are enshrined under the Uthpalavataka Vimanam. The main image of Goddess Lakshmi is worshipped as Kannapura Nayaki while the utsava-murti of this Goddess is called Padmini. This large temple-complex has a stately Rajagopuram in seven tiers in the front.
The Brahmotsavam (annual festival) is in the Tamil month of Vaikasi. A unique feature is that on the seventh day of this festival, the deity gives Darshan as Vishnu during the day, Brahma at night and as Siva the following morning. Many Chola, Pandya and Vijayanagara era inscriptions have been found here. Some mention that this place was called Bhuloka-manikka Chaturvedimangala, situated in the territorial subdivision called Geyamanikka Valanadu.