Dehradun, one of the most important towns of Uttra Khand, located at an altitude of 700 m, serves as the gateway to Mussoorie. The town lies in the Dun Valley, on the watershed of the Ganga and Yamuna rivers. It derived its name from the camp  ( 'Dehra' means camp) of Ram Rai, the son of Hari Rai, the 7th Sikh guru. Apparently, Ram Rai was not made guru after his father, and consequently, disputed the decision. Defeated, he came to Dun Valley, where he was accorded a warm welcome by the Garhwal Raja. In the latter half of the 17th century, Ram Rai established a gurudwara in the Jhanda Mohalla area, which still draws hordes of devotees. 

 During the British Raj, Dehradun was the summer base of the Viceroy's Bodyguard, and transformed into an educational centre and military cantonment. At present, it is also the base of the Indian Military Academy. Dehradun also boasts of the Forest Research Institute, dating back to the British Raj period, and the Wildlife Institute of India.

What To See
Like the Forest Research Institute, the mulberry demonstration farms of the Sericulture Institute, are also one of the highlights of the town. Eight kms from Dehradun, is a popular picnic spot, Gucchu Pani, or Robber's cave. Five kms away is Tapovan, where the legendary Dronacharya, the great guru of the heroes of the Mahabharata, is believed to have performed penance. A monument to the hero of the great siege of Kalanga, Balbhadra Singh Thapa, is also about eight kms from the town. The Sahastradhara, 14 kms away, is renowned for its sulphur springs. The Rajaji National Park, another tourist attraction, is 20 kms away. The site of prime historical interest is Kalsi, 50 kms from Dehradun, which boasts of a rock inscription of Asoka, the great Mauryan emperor. 6 kms from the centre of the town is Tapkeshwar Mahadev, a cave shrine dedicated to Lord Shiva, by the banks of a river. According to a tale from the Mahabharata, Shiva made milk flow from this cave for Asvathama, the son of guru Dronacharya.
Some of the most exhilarating Hill Resorts in India include 
Dalhousie, Himachal Pradesh
Manali, Himachal Pradesh 
Kasauli, Himachal Pradesh
Kulu, Himachal Pradesh
Shimla, Himachal Pradesh 
Dehradun, Uttar Pradesh
Mussourie, Uttar Pradesh 
Pithoragarh, Uttar Pradesh 
Nainital, Uttar Pradesh
Darjeeling, West Bengal
Kodaikanal, Tamil Nadu 
Ootacamund, Tamil Nadu 
Coonoor, Tamil Nadu 
Yercaud, Tamil Nadu 
Lonavala & Khandala, Maharashtra 
Panchgani, Maharashtra 
Mahabaleshwar, Maharashtra 
Pachmarhi, Madhya Pradesh 
Hill Stations of Kerala
Mount Abu, Rajasthan