I took these images while I was a member of the Qala Yampu expedition, a University of Pennsylvania-affiliated archaeological project in Bolivia. The purpose of the Qala Yampu expedition was to investigate how multi-ton stones could have been brought to the Andean city of Tiwanaku some 1500 years ago. Some of the stones originated in quarries on the far side of Lake Titicaca, but the precise methods of transport were unknown. I had focused on this problem in my undergraduate thesis, in which I argued that indigenous reed boats from the region would have provided a viable method for transporting the stones.

The Qala Yampu project included two main components: a large stone and a large reed boat (‘qala’ is the Aymara word for ‘stone,’ while ‘yampu’ means ‘boat’). The stone was a 9-ton monolith that had been selected because its overall shape resembled a famous statue at Tiwanaku, while the reed boat was custom-made for us by an Aymara boat builder whose former clients had included Thor Heyerdahl. In the course of the project the stone and the boat were brought together and the stone was loaded onto the boat. With the stone aboard we successfully sailed across 100 miles of Lake Titicaca, and remarkably, the reed boat never showed the slightest strain under the weight.

Despite the Qala Yampu project’s impressive achievement, it never attracted much attention beyond local Bolivian news coverage, a pair of articles in Penn’s museum journal Expedition, and the little-seen documentary Voyage to the American Stonehenge.  These photographs—never before published—capture people in action at key moments of the project. We see the boat builder and his family shaping the bundles that make up the reed boat. We see a team of workers moving stones using ropes, poles, and their own strength. We see the team loading the stone onto the reed boat with the help of the Bolivian Navy.  We see the voyage across Lake Titicaca and the boat’s celebrated arrival on the shore near Tiwanaku.