Thiruvaiyyaru, the place of five rivers, is a very holy place. The huge temple here is dedicated to Lord Shiva known as Sri Ayyaruappan in Tamil and Sri Panchanadeeswarar in Sanskrit, which means the Lord of the 5 rivers. The Devi's name is Sri Parvathi and is located in a separate temple within the same compound.
Nandeeswarar is the bull vehicle of Lord Shiva commonly called Nandhi. Nandikesar is the founder of the Tiru Kayilaya Parampara-dynasty. Dharumapuram Adheenam and Tiru Avaduthurai Adheenam belong to this heritage. Nandikesar was born to Sage Siladha with four hands. The sage placed the child in a box and opened it then. It was the beautiful child with two hands. He left the child in Tiruvaiyaru. Lord Shiva performed abishek to the child with the breast milk of Mother Ambica, the foam from Nandhi's mouth, nectar-amirtha- Saiva Theertham and Surya Pushkarini Theertham – totally five items – hence, the Lord of the temple is praised as Aiyarappan – Lord of five theerthas.
The architectural skill of the temple is such that multiple echoes could be heard if one loudly calls Aiyarappa standing at a particular place. Foreign engineers had tried to find out this miracle but could not till this day. Of the Navagraha importance, the place belongs to Sun. He is facing west. The temple has five corridors-prakaras. Devotees choose the prayer hall for mental peace and meditation.