In a collaboration funded by the U.S. Department of State, archaeologists are analyzing commercial satellite data, along with U.S. spy satellite and military drone images, which offer a fine-grained view of remote sites that are too dangerous for researchers to visit. At a meeting here last month of the American Schools of Oriental Research, team members said they have more than tripled the number of published archaeological features in Afghanistan, to more than 4500. The discoveries range from caravanserais, huge complexes designed to house travelers and built from the early centuries B.C.E. until the 19th century, to networks of ancient canals invisible from the ground. Meanwhile, octogenarian archaeologists are emerging from retirement to add information from decades-old fieldwork to the site inventory.

“The capability to explore a relatively little known region efficiently and safely is really exciting,” said David Thomas, an archaeologist at La Trobe University in Melbourne, Australia, who has done remote sensing work in Afghanistan but is not a member of the mapping team. “I’d expect tens of thousands of archaeological sites to be discovered. Only when these sites are recorded can they be studied and protected.”


Among the team’s recent finds are 119 caravanserais from the late 16th and early 17th centuries spaced approximately every 20 kilometers—roughly a day’s journey with a large caravan—across Afghanistan’s forbidding southern deserts. The enormous mudbrick buildings typically extended the length of a U.S. football field on each side and housed hundreds of people and thousands of camels. They line routes that linked the capital of the powerful Safavid Empire, Isfahan, in what is now Iran, with the Mughal Empire that then dominated the Indian subcontinent.

The caravans carried enormous amounts of silks, gems, spices, and woods from India, plus porcelain from China and less exotic cargo such as dried fish, says Emily Boak, a UChicago heritage analyst. The regularity of caravanserai construction suggests an ambitious and centrally sponsored effort to ensure a safe and steady flow of goods, she noted. That contradicts previous ideas that the Safavid Empire—which stretched from Turkey to Pakistan and made Shia Islam its official religion by the 17th century—was in decline in this period. 

“There is a long-standing view that once the Portuguese entered the Indian Ocean”—opening sea lanes to Europe in the 16th century—“no one bothered to cross Central Asia,” said project manager Kathryn Franklin, also of UChicago. “But this shows a huge infrastructure investment of the Safavids a century later.”