Take a walk though any landscape in Scotland, and there's a story to be uncovered - of human lives, and the impact we've had on the land around us. Join Iain Stewart as he walks through some of Scotland's most intriguing landscapes, guided by people who live and work in them, to uncover tales of how we have exploited, celebrated and enjoyed Scotland's forests, hills, lochs, glens and shores. In this programme, Earth, Iain visits Glen Lui, in the heart of the Cairngorms National Park. As he walks up the glen towards the mountains, he learns that the area has long been a playground for visitors - and how that recreational history still shapes the glen today.