The Thamirabarani River (also spelt Tamaraparani, Tamiraparani, or Thamiravaruni) originates from the famous Agastyarkoodam peak in the hills of the Western Ghats above Papanasam in the Ambasamudram taluk and flows through Tirunelveli and Tuticorin districts of the Tamil Nadu state of southern India. It was called the Tamraparni River in olden days, a name also associated with Sri Lanka. The old Tamil name of the river is Porunai.