Wether you are eating maggi in robbers cave or drinking sulphir water in sahastradhara. Dehradun has a lot to offer you than just sightseeing.
You can enjoh all the delicacies of food as well as nature. Go for a trip to Mussorie which is only 20 km from dehradun and also try river rafting in the volumnous water of Ganga at Rishikesh.