Adi Kumbeswarar Temple is the major one among the Saivite temples and located in the centre of Kumbakonam at Big Bazaar Street. Shri Adhi Kumbeswara is the presiding deity of Kumbakonam and Manthrapeeteswari Mangalambika is the lord’s Consort. The temple complex is huge and has beautiful artwork. This temple covers an area of 30,181 Square Feet with a length and breadth of 750 feet, and 252 feet respectively. This temple comprises three Praharas and three Gopurams in the eastern, northern and western directions. It is believed that Govinda Theeksithan, the Chieftain of Achutha Nayakar of Thanjavur, renovated this oldest temple during the 16th century. The East Gopuram consists of 9 stories with a height of 128 ft (39 m). Mangala Theertham, Marriage hall and small temples for Muruga, Ganapathi and Mangalambigai are other major constituents of this temple. Lord Shiva announced that the Mango brought by Sage Narada would be presented to one who wins a marathon round of the whole world. Lord Vinayaka circumambulated His divine parents Shiva and Parvathy and established the fact that the world means Father and Mother and going around them fulfilled the condition of competition. He won the mango. Based on this philosophy, the pra kara structure of the temple covers both Lord and Mother shrines. In other temples, the pra karas are separate. There is no Abhishek to the presiding deity. The Linga is broad in a base and sharp at the top as a needlepoint. The stones of the temple have musical tones. There is a lion sculpture in the Navarathri Mandap holding long stones on its head.

The Pottramari tank – tank with golden lotus flowers – is in front of the temple. Those coming for the bath in Mahamagam tank bathe in this tank also. After their bath in the former tank, it is said that the Navakannikas bathed in this tank also. Hence, this is practised. Kumbamuni Siddha is in the outer corridor of the temple. Devotees pray here for relief from the adverse aspects of planets.

Mother Goddess is praised as Mangala Nayaki and Mantra Peeta Nalathal. Sage Tirugnana Sambandar in his hymns had praised Mother as Valar Mangai. Lord Shiva parted half of His body with Mother Parvathi, He had also parted 36 crores of His Mantra Shakti-power with Her. Mother also has Her share of 36 crores Shakti and the share of Lord make it to 72 crores. Thus Mother is praised as Mantra Peeteswari. Of the 51 Shakti Peetas, this the first place. She wears the yellow sari with turmeric on the face and the Kumkum on the forehead. She glitters with all mercy.

The Mahamaha tank measures 3 acres situated in the heart of the Kumbakonam town. During the Pralaya floods, when nectar flowed from the pot, Lord Shiva made it fall into a pit on earth. This pit is the Mahamagam tank. The Kumbakonam Mahamagam festival is celebrated once in 12 years on a Poornima-full moon day when Jupiter enters Kumba-Aquarius and Sun Simha zodiac signs. On this day, other holy rivers Ganga, Yamuna, Godavari, Narmada, Saraswathi, Cauvery, Kumari, Bayodhini and Sarayu also bath in the tank to cleanse themselves of their sins. It is also believed that those bathing on this day in the tank, takes the benefit of seven families related to them.

Lord Vinayaka of the temple is praised as Aadhi Vinayaka as He had arrived here well before Lord Shiva and Mother Parvathi to the place. Lord Muruga had received the Mantra Upadesa from Mother Mantra Peeteswari before waging the war against Sura Padma. He is praised by Saint Arunagiriar in his Tirupugazh hymns. Lord Shiva came here in the guise of a hunter (Kiradha) and broke the nectar pot here. Special pujas are dedicated to Him on the Magam star days by devotees to realise their wishes.