The Uppanar river, is a significant distributary of the Cauvery River in flowing through the coastal Sirkazhi and Tharangambadi taluks of Mayiladuthurai district, in the southern state of Tamil Nadu, India.
The Uppanar distributary system includes several engineered branches, often designated as A, B, C, and D in government and hydrological records. The Uppanar Rivers A, C, and D flow through the Mayiladuthurai district, whereas Uppanar River B flows through the Cuddalore district.
Tharangambadi (Tamil: [t̪aɾaŋgambaːɖi]), formerly Tranquebar (Danish: Trankebar, pronounced [ˈtsʰʁɑŋkəˌpɑˀ]), is a town in the Mayiladuthurai district of the Indian state of Tamil Nadu on the Coromandel Coast. It lies 15 kilometres (9.3 mi) north of Karaikal, near the mouth of a distributary named Uppanar of the Kaveri River. It was established on 19 November 1620 as the first Danish trading post in India. King Christian IV had sent his envoy Ove Gjedde who established contact with Raghunatha Nayak of Thanjavur. An annual tribute was paid by the Danes to the Rajah of Tanjore until the colony was sold to the British East India Company in 1845.
Tharangambadi is the headquarters of Tharangambadi taluk. Its name means "place of the singing waves"; the old designation Trankebar remains current in modern Danish. Tharangambadi is located at the distance of 285 km from Chennai. The nearest airport is Tiruchirappalli International Airport, 172 km away and the nearest port is at Karaikal at 26 km. It is served by Tharangambadi railway station.