nature and heritage in the doon valley, dehradun

architecture surroundings destinations uttarakhand educational environment gucchupani landscapes historical institute himalayan foothills cityscape mussoorie landmarks buildings adventure undefined dehradun research colonial shivalik cultural tranquil greenery heritage mountain peaceful retreats robbers natural tourism streams valleys vibrant station valley forest scenic beauty indian iconic serene golden trails gorges sunset nature hills views rocky spots doon cave life lush hour city hill hub