The Aranmula Vallamkali, the world famous water festival is the main important event related to this place. It started in relation with the Thiruvonathoni which starts on Uthraadam (day before Onam)evening from Kaattoor Mahavishnu temple with provisions for the ''Nivedyam'' and ''samoohasadya'' (mass feast)on Thiruvonam at the temple. The provisions are offered by the Mangattu Bhattathiri, the karanavar (the eldest member) of Mangattu Illom. (There is also a legend behind this.) Previously, the Mangattu Illom was situated near Kattoor temple and now it is at Kumaranalloor near Kottayam. There will be a representative from the family on the thoni (canoe), as part of the tradition. It is a nice sight to see the thoni moving down the river Pampa without rowing. The thoni is symbolic of Garuda the vehicle of Lord vishnu
Dedicated to Lord Sree Krishna, this temple siutated on the banks of the holy River Pamba, attracts large crowds of devotees. It is said that the idol was brought here in a raft made with aru (six) pieces of mula (bamboo) which gave the town its name, Aranmula. Various cultural organisations at Aranmula imparts training in traditional arts like Kathakali, classical dances, classical music and Kalaripayattu. Tourists stay here for long periods to get first hand knowledge of the culture of Kerala. The temple has fine murals of the 18th century.