The Pathanamthitta Town, which is the administrative capital of the Pathanamthitta district is situated along the river. The town derives its name from its association with the river; Pathanamthitta, from the Malayalam words pathanam and thitta, means "houses by the riverside".
A small village situated in its upper riparian area of the river is called as Achenkovil village. The Achenkovil village is an important pilgrimage center which is associated with the legend of Sabarimala and it is also one of the important interstate border point between Kollam district and Tenkasi district.[5]
Achankovil Shastha Temple, or the Dharmasastha Temple, is one among the five important temples dedicated to Lord Ayyappa in Kerala. Lord Ayyappa leads the Grihastha Ashrama life here – he is depicted as a family man or leads married life here. He is depicted along with his two wives – Purna and Pushkala. It is believed that the idol here was installed by Parashurama.[6]
The Achankovil Sastha Temple is famous for curing poisonous snake bites. The left hand of the idol of Ayyappa at Achankovil Shastha Temple always holds ‘Chandan’ (sandalwood paste) and Thirtha (holy water).[7] The Chandan and Thirtha are considered to have medicinal properties to cure snake bites. The temple complex also contains other deities associated with the Ayyappa legend. The festivals and rituals held here have strong Tamil roots.
During the Sabarimala pilgrimage, devotees also visit this temple to offer their prayers. It is believed that the idol of this temple was consecrated by Sage Parasurama. On both sides of the idol, Poorna and Pushkala, the consorts of Lord Sastha are also installed. The most important festival here is celebrated from the first to tenth day of Malayalam month Dhanu (December – January).
Achenkovil shear zone
In geology it is a major crustal discontinuity of Proterozoic age which separates Kerala Khondalite Belt (KKB) in the south (Trivandrum Block) from the Charnockite massif in the north (Madurai Block).[8] The Achankovil river drains this structural valley.[9] There are geologists who argue that this shear zone is a vital link that bears imprints of land connection between India and Madagascar when both this land masses were part of Gondwanaland.[10]
The river is unique in that along its route is a large number of ancient temples, indicating that the richness of the river basin has been identified by humans since ancient times and they preferred to settle down there so that they could grow their crops on the fertile lands.
Entrance to Thrippara Shiva Kshetram on the banks of River Achankovil
The Karingalichal wetlands spread over Pandalam Municipality, Nooranad and Palamel Panchayaths, a place famous for its flora and fauna, is on the banks of the Achankovil river.[11]
The river basin had active Buddhist settlements in the Middle Ages. The present day Chamakkavu Sharngakavu Devi Temple near Venmony a Hindu Temple, was a Buddhist place of worship, which was transformed initially into a Vishnu temple (then known as Sharnga-kavu) and later into a Devi temple. The annual chariot festival and other traditions correspond to the old Buddhist practices of "kettu kazhcha", which was assimilated into Hinduism in Kerala. The Karumadikkuttan statue and Buddhist relics found near Mavelikkara further underscores this.[12][13]