Snow. It's fascinating, entrancing, elusive and ephemeral, and a metaphor for life. Exploring my own thoughts, and those of Wilson Bentley and Loren Eiseley on snow.

On two expeditions to the Sky Tombs of Upper Mustang, Nepal, I was able to film and photograph an amazing team of climbers and scientists as they pieced together the ancient history of the region.

We tend to focus on the summit as the sole barometer of success - on mountains and in life - but come to find the top of the mountain is just a small part of the journey.

A moment and memory from Western Tibet as I followed the Langqen Zangbo (Sutlej) River from Tirthapuri to Tholing in 2006.