Located in Eramallur, Alappuzha district, Chennamana Siva Temple is a rare and historically significant stone-built medieval Kerala architecture temple dating back to the 13th century CE. The temple sits in a picturesque valley, surrounded by paddy fields on three sides, and is an excellent example of a circular Vimana (Ekatala Alpavimana) following the Sandhara style, which includes a circumambulatory passage inside. The Sreekovil (sanctum sanctorum) features a unified conical roof, paved with small tiles. The entrance is guarded by two-armed Dwarapalakas. The principal deity, Lord Siva, is enshrined facing south, while Goddess Parvati is enshrined at the back of the Sreekovil, facing north. The temple also houses more sub-shrines dedicated to Ganapathy, Sastha, and Rakshas. The Garbhagriha (sanctum) is a square chamber with a square Sikhara above it, housing a Shiva Linga on a square Peeda. An open Balipida is installed on the eastern side. The walls of the Sreekovil are built entirely of stone, featuring pierced window frames and an array of Kostha Devatas on the Gavakshas, arranged in a clockwise direction. The Makara Torana scheme decorates the false doors on the northern and southern sides, while a Pranala (drain spout) is set into the northern Kantha. The plinth consists of moulded tiers, including Vritha Kumuda, Kanta, and Kapota, topped with a Vedika. Vattezhuthu inscriptions on the Adhishtana reveal that the temple’s construction began in 446 M.E. (1271 CE) and was completed in 448 M.E. (1273 CE) under the supervision of Chathannur Varian Devan Uzhuthiran. The total cost of construction, excluding the Peedam and idol, was 105 'Achu', a currency in circulation at that time. The work was overseen by Koyilpalli Sankaran Chathan. Originally managed by the landlords of Mamballi Madom in Chengannur, the temple is now under the administration of the N.S.S. Karayogam of the locality. In 2005, the Department of Archaeology undertook scientific conservation of the conical-shaped superstructure, including the temple door, preserving this ancient architectural marvel for future generations.