Both Skardu and Gilgit have short flights from Islamabad (about an hour each). They are the fastest way north and one of the most scenic flights anywhere - but they come with a catch.
The reality
- Weather-dependent: these are visual-approach mountain flights, cancelled often, sometimes for days in a row.
- Always keep a buffer day and a road back-up. Never book the flight on the last morning before an onward international connection.
- Book early in peak season (June-August); seats sell out and fares rise.
The reliable alternative is the Karakoram Highway by road (about 20-24 hours, split over two days). Many travellers fly one way and drive the other. See Skardu and Gilgit-Baltistan packages, and the road status.