Sonbhadra (also known as Sonebhadra) or Sonanchal is the second largest district by area of Uttar Pradesh after Lakhimpur Kheri.

[5][6] The Valley of Son and Belan Rivers abounds in caves which were the earliest dwellings of the primeval inhabitants.

[8] It is said that 'Bhars' had settlements along with Chero, Searis and Kharwar communities in the district up to fifth century there was the rule of ''Chandel Rajput'' kings on Vijaygarh Fort.

After the death of Harshvardhan in the latter half of the 7th century, it remained under the control of the Gurjara-Pratihars till 1025 before they were driven out by Mahmud of Ghazni.

The heroine of Famous Novel Chandrakanta written by Devaki Nandan Khatri was the princess of Vijaygarh and the daughter of king Jay Singh.

The northern part of the district lies on a plateau of the Vindhya Range, and is drained by tributaries of the Ganges including the Belan and Karmanasha rivers.

South of the steep escarpment of the Kaimur Range is the valley of the Son River, which flows through the district from west to east.

East of the Rihand, the Kanhar River, which originates in Chhattisgarh, flows north to join the Son.

The portion of the district north of the Son River lies in the Lower Gangetic plains moist deciduous forests ecoregion.

The portion south of the Son lies in the Chhota Nagpur dry deciduous forests ecoregion.

Kaimoor Wildlife Sanctuary lies mostly within the district, reaching generally east and west along the spine of the Kaimur Range, and extending to the Son River at its eastern end.

[citation needed] In 2006 the Ministry of Panchayati Raj named Sonbhadra as one of the country's 250 most backward districts (out of a total of 640).

Robertsganj, the headquarters of Sonbhadra, is located about 88 km (55 mi) from the city of Varanasi which has the nearest airport.

Robertsganj is well connected to Lucknow, Allahabad, Varanasi, Mirzapur, Gorakhpur, Faizabad, Ambikapur Sasaram & Garhwa by road.

Though this is not a national highway it is a very busy road because of the towns Dalla, Renukot, Anpara, Shaktinagar which are sufficiently commercialized areas.

National Thermal Power corporation is in Shaktinagar and also Northern Coalfields limited (a subsidiary company of Coal India Ltd) has different projects like Singrauli, Khadia, Jayant, Dudhichua, amlori, Kakri etc.

Churk a nearby town is situated around 10 km (6.2 mi), where Jaypee Group is establishing a thermal power project.

One of the main reasons this road is always busy is due to daily transport of around 1000 trucks of grits and sand.