Head on over to Sahastradhara and spend a quiet afternoon meandering along the water's edge. There's something about being by a river that makes you feel calm and relaxed.
You'll soon see why this Uttarakhand flowing body of water is visited by many travelers. If you're looking for other things to keep you busy, Mussoorie Lake, Robber's Cave, and Gun Hill are in this area too. They won't take you very long to get to from Sahastradhara Natural Spring.