DehraDun is an excellent place with awesome weather and pollution free air. It holds a lot of significance from history point of view. There is Forest Research of India(FRI), a building constructed by Britishers(you can imagine the age of the building now), there is SahastraDhara where you can find sulphur water springs, mussoorie is the famous hill station near by.
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The place also has other spots like Budha Temple, Tibettan Monestry, Renuka Jheel, Kalso, VikasNagar etc.