Padmanabhapuram was the erstwhile capital of the princely state of Travancore in India. The Travancore King, Rama Varma, who was popularly known as Dharma Raja, shifted the capital in 1795 from Padmanabhapuram to Thiruvananthapuram. By that time, the boundaries of the Travancore had extended to half of the present day Kerala State. Up to 1957, Padmanabhapuram formed part of the Travancore Kingdom and subsequently the Travancore-Cochin State. It was when the States were divided on linguistic basis that Kalkulam (including Padmanabhapuram), Vilavancode, Thovala and Agastheeswaram Taluks of erstwhile Thiruvananthapuram District of the then Travancore- Cochin State were included in the then Madras State (later renamed as Tamil Nadu) as Kanyakumari District.
Padmanabhapuram is located at 8.23°N 77.33°E / 8.23; 77.33. It has an average elevation of 15 metres (49 feet).
According to 2011 census, Padmanabhapuram had a population of 21,342 with a sex-ratio of 1,029 females for every 1,000 males, much above the national average of 929. A total of 2,120 were under the age of six, constituting 1,084 males and 1,036 females. Scheduled Castes and Scheduled Tribes accounted for 10.61% and .% of the population respectively. The average literacy of the town was 83.92%, compared to the national average of 72.99%. The town had a total of : 5549 households. There were a total of 7,036 workers, comprising 54 cultivators, 388 main agricultural labourers, 87 in house hold industries, 5,481 other workers, 1,026 marginal workers, 16 marginal cultivators, 73 marginal agricultural labourers, 54 marginal workers in household industries and 883 other marginal workers.
The popular Padmanabhapuram Palace, the old palace of the Travancore kings, is also located here. It is spread over an area of 6 acres (24,000 m2). The palace is known for it antiques, including the armoury of the royal family. The woodwork in this palace is intricate. This Palace is maintained by the Govt.of Kerala Archaeology Department.
Other tourist locations include Thirparappu Waterfalls, Hanging Bridge in Mathoor, Ancient Jain Temple in Chitharal (a small village situated at a distance of 8 km from Marthandam.) Thiruvalluvar Statue in Kanniyakumari. One can take a bus from Thiruvananthapuram or Nagercoil and get down at Thuckalay, which is two kilometres away from Padmanabhapuram. The nearest places around this old capital city of South travancore is Marunthukottai (It is a very old fort having weapons storage facility), Saralvilai, Kumarakovil (Lord.Murugan Temple), Moolachel, Charode, Manali, Udaygiri fort ...
There are many temples around Padmnanbhapuram Place, Padmanabhapuram Madan-Ishakkiamman Temple, Padmanabhapuram Bhuththan Temple, Padmanabhapuram Pillayar Temple, Padmanabhapuram Murgan Temple, Ramaswamy Temple, Padmanabhapuram Sarswathy Amman Temple, Perumal Temple, Neelakandaswamy Temple and Padmanabhapuram Chettu Samudhaya Mutharamman Temple Thirukarthikai is the famous festival celebrated at Padmanabhapuram Chettu Samudhaya Mutharamman Temple.
Padmanabhapuram assembly constituency is part of Nagercoil (Lok Sabha constituency).