We were two days' walk past Laayoune, the last city and supply drop for the next 30 days, and our little caravan of three Amazigh (Berber) guides, one Scot and six camels had just entered the grand dunes.
They shimmered under the sun, as much silver as gold and seemed to move as I stared at them. After endless days of walking on the flat, the curves felt voluptuous. The dunes are a killer for the legs, so we skirted them, walking the edge of a large sunken valley called a sabkha, which is deep red in places, signifying the possibility of quicksand. "My legs have got a headache," said Addi, the youngest of my travelling companions at 24 and the son of a nomad. I knew exactly what he meant.
The Sahara Expedition was a three-month long crossing of the world's biggest hot desert from Oued Chbika on Morocco's Atlantic coast to Guerguerat on the Mauritanian border. The history of this Western Sahara region is a complex and troubled one and although it is governed by Morocco, the UN has recognised that the people of the region, the Sahrawis, have a right to self-determination. The expedition was a physical challenge as we crossed over 2,000km, walking around a half-marathon a day for 78 days, but the aim was exploration. I wanted to see what life was like there now, what traces history had left behind and also what the impact of climate change was on the region.