In the 1950s, J. Desmond Clark found a notched log at Zambia’s Kalambo Falls but died without proving its age; 60 years later, dating revealed the world’s oldest wooden structure at 476,000 years

For decades, a strange piece of wood buried near Zambia’s Kalambo Falls carried a question that archaeology could not answer. Was its unusual notch carved by an ancient human relative, or had nature produced the shape by chance? J. Desmond Clark, who excavated the site in the 1950s, believed the answer was human craftsmanship. But the technology of his time could not prove it. More than half a century later, new excavations and a more suitable dating method finally gave the old discovery its context. The result was extraordinary: two logs had been deliberately shaped and joined at least 476,000 years ago.

A strange piece of wood at Kalambo Falls