The area in the eastern part of the state of Madhya Pradesh and the adjoining southern part of Sonebhadra district in the state of UP is collectively known as Singrauli Region. Singrauli is emerging as India's energy capital. The place earlier known as Shringavali, named after the sage Shringi, was once covered with dense and unnavigable forests and inhabited by wild animals. The place was considered so treacherous that it was used by the kings of Rewa State, who ruled the area till 1947, as an open air prison for detaining errant civilians and officers.