Sonbhadra or Sonebhadra is the second largest district by area of Uttar Pradesh after Lakhimpur Kheri. It is the only district in India which borders four states, namely Madhya Pradesh to the west, Chhattishgarh to the south, Jharkhand in the south-east and Bihar to the north-east. The district has an area of and a population of 1,862,559 (2011 census), with a population density of . It lies in the extreme south-east of the state, and is bounded by Mirzapur District to the northwest, Chandauli District to the north, Kaimur and Rohtas districts of Bihar state to the north-east, Garhwa district of Jharkhand state to the east, Balrampur District of Chhattisgarh state to the south, and Singrauli district of Madhya Pradesh state to the west. The district headquarters is in the town of Robertsganj. Sonbhadra district is an industrial zone and it has much bauxite, limestone, coal, gold, etc. It is called the "Energy Capital of India" because there are multiple power plants. Sonbhadra lies between Vindhya and Kaimur hills, and its topology and natural environment prompted First Prime Minister of India Jawaharlal Nehru to refer to Sonbhadra as the "Switzerland of India". In 2018 Uttar Pradesh's chief minister Yogi Adityanath recognised Sonbhadra as a tourist hub in Purvanchal region and further promoted by Uttar Pradesh Tourism Department. In February 2020, a Press Trust of India (PTI) news report incorrectly claimed that Geological Survey of India (GSI) has found of gold deposits in Sonbhadra district. PTI later clarified on Twitter that the GSI had told PTI that there had been no such discovery of large gold deposits in the district. History The Valley of Son and Belan Rivers abounds in caves which were the earliest dwellings of the primeval inhabitants. This area had been the centre of activities of pre-historic man which is evident from the rock paintings (pre-historic cave art) found in abundance in this region. These paintings are of the periods ranging from Mesolithic to Paleolithic ages. Based on evidence from religious and cultural perspectives of Ramayana and the Mahabharat, Huyen found here is the cultural symbol. By Jarasandh many rulers in the Mahabharat were maintained prisoner here. Sonbhadra, whose ancient name was Gramputra or Gupt Kashi, was built by the ancient king Putrak for his queen Paatali. It is said that 'Bhars' had settlements along with Chero, Searis and Kharwar communities in the district up to fifth century