'Onakanthantali' is named after the two demons, Onan and Kaanthan, who were the army commanders of King Vanasuran. The temple features a modest 3-tier Raja Gopuram and has three sanctums. The gateway leads to the prakaram which houses a Nandi and Balipeetam. Two Shiva Lingams which were worshipped by the two demons Onan and Kaanthan, named Oneshwar and Kantheshwar are in two separate sanctums. Foremost is Oneshwar, a Swayambu Linga, facing east. Behind the Swayambhu Linga, we can see Shiva-Parvathy as bride and groom in their 'Tirumana Kolam'. Within the 'Artha Mandap' of this sannidhi, is an idol of Sundarar. The second sannidhi is dedicated to Kantheshwar, and the the third is dedicated to Chalandhareshwar, who is said to have been worshipped by Chalandhara. This sannidhi was consecrated at a later period. Sundarar mentions about the sannidhi of 'Vayirudhari Pillayar' in his pathikam. Apart from this, Another Vinayaka called 'Omkara Vigneshwar' can be seen outside the sannidhi of Kantheshwar. It is said that, one can perceive the sound of 'Om' when they place their ears close to the idol of "Omkara Vigneshwara." Dakshinamurthy is depicted with one foot on the demon 'Muyalaka' in the presence of the Sanakadhi Sages.