Neriamangalam Dharma Sastha temple is located on the Kothamangalam – Adimali road in Ernakulam district, Kerala. The annual festival at Neriamangalam Sastha temple is observed for 6 days during Makaravilakku or Makara Sankramana.
The main rituals held during the festival are Ashta Abhishekam, Deepa Kazhcha, Sri Bhootha Bali, Kodipurathu Vilakku, Sri Bali, Navagam, Panchagavyam, Utsava bali, and Arattu ezhunellippu on the final day.
The main deities worshipped in the temple are Shiva and Dharma Sastha. More importance is given to Sastha in the temple.
The Upa Devatas worshipped in the temple are Ganapathy, Nagam and Malikapurathamma.
The shrine is on the banks of Periyar River. This is one among the 108 Ayyappa temples in Kerala. The shrine is known as Choliyal Kavu in Thottam Pattu which narrates the glory of 108 Sastha temples in Kerala.