Camels cast shadows across the Qala-e-Bost arch in southern Afghanistan’s Helmand province. The 11th century arch, which appears on the 100 Afghani note, marks the principal approach to the ancient fortress citadel of Bost, later renamed Lashkar Gah.

Over the centuries, the city bore multiple assaults by the Ghorids, Genghis Khan, and Tamerlane. Today it is the capital of the Helmand province.

(Photo shot on assignment for, but not published in, “Afghanistan: Crossroad of Conquerors,” September 1968, National Geographic magazine)