Dehradun (/ˌdɛrəˈduːn/) is the winter capital, largest city and also the most populated city in Uttarakhand. it lies along National Highway 7 with the distance of 248 km (154 mi) north of India's capital New Delhi and is well-connected with a rail line (Dehradun railway station) and the airport (Jolly Grant Airport). Dehradun is one of the "Counter Magnets" of the National Capital Region (NCR) being developed as an alternative centre of growth to help ease the migration and population explosion in the Delhi metropolitan area and to establish a smart city in the Himalayas. It is the third largest city in the Himalayas after Kathmandu and Srinagar.
Dehradun is located in the Doon Valley on the foothills of the Himalayas nestled between Song river, a tributary of Ganga on the east and the Asan river, a tributary of Yamuna on the west. The city stands at an elevation of 640 metres (2,100 ft) above sea level. Also known as the 'Abode of Drona', Dehradun has been an important center for Garhwal rulers and was captured by the British.
The history of the city of Uttarakhand, Dehradun (nicknamed "Doon Valley") is linked to the story of Ramayana and Mahabharata. It is believed that after the battle between Ravana and Lord Rama, Lord Rama and his brother Lakshmana visited this site. Also, known as 'Dronanagari' on the name of Dronacharya, legendary Royal guru to the Kauravas and Pandavas in the epic Mahabharata, is believed to have been born and resided in Dehradun. Evidences such as ancient temples and idols have been found in the areas surrounding Dehradun which have been linked to the mythology of Ramayana and Mahabharata. These relics and ruins are believed to be around 2000 years old. Furthermore, the location, the local traditions and the literature reflect this region's links with the events of Mahabharata and Ramayana. Even after the battle of Mahabharata, the Pandavas had an influence on this region as the rulers of Hastinapura with the descendants of Subahu ruled the region as subsidiaries. Likewise, Rishikesh is mentioned in the pages of history when Lord Vishnu answered the prayers of the saints, slaughtered the demons and handed the land to the saints. The adjoining place called Chakrata has its historical impression during the time of Mahabharata.