Dehradun, the city, headquarters of the district is visited by a large number of tourist every year, many of them en-route to Mussoorie. The climate of the city is temperate. Even during summer, it is not so warm at Dehra Dun as in the district south of it. The Forest Research Institute which is world famous for its research work in forestry and is the only institution of its kind in Asia is situated here. Besides, headquarters of the important establishment like the Oil and Natural Commission; Survey of India etc., the Military Academy are also located here. The Gurudwara built by Guru Ram Raj during the reign of Aurangzeb in the Dhamanwala locality o the town is a religious place of eminence. The other places of importance is the Robber's cave, situated at a distance of about 8 kms from Dehra Dun. The cave is a natural picnic spot surrounded by hills where water suddenly disappears from sight and goes underground only to reappear after a few yards in the form of a stream. The city has many beautiful rest houses and good hotels to provide accommodation to the tourist. For many years, it has been one of the best known educational centres in northern India. Dehra Dun is well linked by rail and road with Delhi, Bombay, Calcutta, Lucknow and Varanasi.