Kanyakumari district, officially Kanniyakumari district, is one of the 38 districts of Tamil Nadu state and the southernmost district in mainland India. It stands second in terms of population density among the districts of Tamil Nadu. It is also the richest district in Tamil Nadu in terms of per capita income, and also tops the state in Human Development Index (HDI), literacy, and education. The district's headquarters is Nagercoil.