Nestled in a serene forest glade, the Mannarasala Sree Nagaraja Temple in Alappuzha District is renowned for its unique setting and significant religious importance. This temple, dedicated to the Serpent Gods, features over 30,000 snake images along its paths and trees. What sets it apart is that it is presided over by a Brahmin woman, making it one of the rare temples with a female priestess. The temple's major festival, the Ayilyam Festival, falls on the Ayilyam asterism in the Malayalam month of Thulam, which corresponds to October/November.

The festival's highlight is the grand procession, or Ezhunallathu, where serpent idols from the temple and the sacred grove are carried to the Illam, the ancestral Brahmin home that manages the temple. The priestess, Valiya Amma, leads the procession, carrying the idol of Nagaraja, the presiding deity. Special prayers and offerings are performed at the Illam, creating a spiritually charged atmosphere.

The Mannarasala Ayilyam festival, celebrated in Thulam, gained prominence due to an interesting historical event. It was customary for the Maharaja of Travancore to visit the temple on Ayilyam day in the month of Kanni. However, one year, the Maharaja had to postpone his visit to Ayilyam day in Thulam. The royal palace funded the celebrations, giving the festival a regal grandeur that continues to this day. Ayilyam days in Kanni and Kumbham are also celebrated with great enthusiasm, marking the birthdays of Nagaraja and Anantha, respectively.

During Ezhunalathu, Valiya Amma carries the idol of Nagaraja, followed by Cheriya Amma with the idol of Sarpayakshi Amma, and two senior male members carrying the idols of Nagayakshi Amma and Nagachamundi Amma. The procession reaches the Illom where the priestess performs her daily Thevaram and the Ayilyam Pooja. While Ayilyam Pooja is conducted on every Ayilyam, the Ezhunallathu procession is unique to the months of Kumbham, Kanni, and Thulam.

Another significant ritual associated with the festival is the Pulasarpam Pattu, an annual offering in Pulakkavu, located northeast of the Illom. The primary pooja here is Nurum Palum, performed by Valiya Amma, particularly on Ayilyam day in Kumbham or subsequent Ayilyams.

The Mannarasala Ayilyam festival is not just a religious observance but a cultural spectacle that attracts devotees and visitors from far and wide, immersing them in the mystical traditions and serene beauty of the temple.