The Siva Temple at Thiruvanchikulam in Kodungallur is one of the earliest and most ancient temples in Kerala and is of great historic importance. It is said that here the Saivite saint Sundarmoorthy Nayanar and his royal friend Cheraman Perumal worshipped Lord Siva and attained eternal bliss and reached Kailas by mounting a thousand-tusked white elephant and a blue horse respectively. It happened on Swati day in the month of Karkidakam (August-September) and it is also believed that the "Kollam" Era (Malayalam) started from that day. Every year there are special poojas conducted at their shrines in this temple. When Umamaheswara appeared in this place once surrounded more by paddy fields Vasuki the godly serpent and holy nagas (serpents) stood guard and worshipped the divine one and the priceless treasures beneath the idol. This self-incarnated Linga in the present Sanctum Sanctorum' of the temple is only some four inches above the ground level and is in the form of a half circle, 12" in diameter. There is water all around, believed to be the Ganga. One Malayali Brahmin (Namboothiri) was fortunate to take away the Vasuki the Holy Naga King, on a palmyra leaf umbrella to his home (Mana or Illom) by the grace of Vanchulesa and it is believed that the Namboothiri family, now famous in Kerala as Pambummekkatt Illom, prospered afterwards by worshipping the Nagas. This Illom is some six miles east of this shrine. Over the head of the idol, more towards the left side, there is a scar mark. The legend has it that when the Lord with his consort Maheswari appeared before Arjuna in the forms of Kiratha and Kirathi (hunter and huntress) Arjuna mistakenly beat at the forehead of the Lord making this mark. On the left side of the front of the Mukhamandapam (entrance), a stone carving depicting Siva and Parvathy could be seen. It is also said that Uma and Maheswara appeared here as Ardhanareeswara, the left side of the idol representing, Naari (Uma) and the right, Naran (Maheswaran). The main and most coveted ritual to Vanchulesa is Dhara, the non-stop pouring of water, and Abhishekam with the chanting of Rudra Manthram. Ekadasa Rudram, Sankha abhisheka, Mrithyunjaya havanom etc. are believed to be very efficacious. Uma Maheswara Pooja or Dampathi Pooja is a speciality here. The main festival is in the month of Kumbham. It lasts for eight days commencing on the Ashtami day of Krishna Paksha as Kodiyettam (Flag hoisting) and Arattu on the Amavasi day after Sivarathri. Arattu is conducted at the sea, 4 miles west of the temple.