Nagapattinam District was formerly a part of Thanjavur District. The district boundary is shared by Tiruvarur, Karaikal, Tanjore and Cuddalore districts. Its population at the 2001 Census was nearly 1.5 million. The district has seven taluks, eleven administrative blocks, eight town panchayats, and four municipalities. Five of the talukas are coastal, and all are named after their main towns, which are their administrative centres. From north to south, they are Nagapattinam, Kilvelur, Thirukkuvalai (non-coastal), and Vedaranyam. It is bordered on the east by the Bay of Bengal and on the south by the Palk Strait. On the coast between Tharamgambadi and Nagapattinam lies the small district of Karaikal, an enclave belonging administratively to the Puducherry Union Territory. This is the only district in Tamil Nadu to be formed out of two disjoint regions. The district headquarters, Nagapattinam, is located in the southern part which is less populated than the northern one.