On a global walk, mass migrations and China's rise are seen at boot level

Paul Salopek leads his two cargo camels in the Afar region of northeastern Ethiopia soon after the Out of Eden Walk began.

African migrants crowd the night shore of Djibouti, trying to capture inexpensive mobile signals from neighbouring Somalia—a tenuous link to relatives abroad.

Night camp: Salopek winds down among the Nabatean ruins of Madain Saleh, in the Hejaz region of Saudi Arabia.

Abdullah, 12, from Mecca, tends camels after taking them for a walk in the desert near Yanbu, Saudi Arabia. Wealthy camel owners generally hire boys to care for their herds.

Worshippers participate in the 'holy fire' ceremony in the Church of the Holy Sepulchre in Jerusalem's Old City.

Salopek and his cargo mule, Kirkatir, make their way through the countryside near Nemrut, in eastern Turkey.

With their home in Ayn al Arab, Syria, under attack, ethnic Kurds push toward a barbed wire fence at the Turkish border.

In Kazakhstan, Salopek and his horse, Alex Moen, arrive at the Yesmambet-Ata necropolis.

Surrounded by friends and relatives, a five-year-old boy has just undergone a traditional circumcision at his home in Khiwa, Uzbekistan.

Last steps in the Wakhan corridor: the gruelling ascent to Irshad Pass, Afghanistan's 5,000-metre gateway to Pakistan.

In the village of Qala-e Panja, in the Wakhan corridor, Wakhi women celebrate Eid-e Qurban, the Muslim holiday of sacrifice.