Mussoorie was built by the British in 1823 to escape the heat of the plains, and it has been doing that job ever since. It sits at about 2,000 metres on a ridge above the Doon valley, close enough to Delhi for a long weekend and high enough that the air changes completely.
Most visitors do Kempty Falls, walk Mall Road, and leave. That is a shame, because the best of it is slightly further out — Lal Tibba on a clear morning, the Buddha at Dalai Hills, and above all Landour, the cantonment above the town where the deodars close over the road and nothing much has happened since 1825.
This is a gentle trip. No altitude to speak of, short drives, and enough time built in to sit still. It works particularly well as a first India journey, and as a family one.
Dehradun→Mussoorie→Landour