The source said the structure was found along a riverbank in Zambia, and consisted of two interlocking pieces of wood, with a slit in the upper piece so that it corresponds to the second piece at right angles.

Jeff Doller, professor of geography and earth sciences at Aberystwyth University in the UK, was part of the team that found the structure in 2019.

Doller said the wooden structure was excavated upstream of the Calambo Falls near Zambia's border with Tanzania.

It is believed that this piece was part of a wooden platform used as a corridor, to keep food or firewood dry or perhaps as a base for building a dwelling on it. A drill stick and other wooden tools were found at the same site.

"For wood to remain in place and intact for half a million years is unnatural," Doller added.

"The structure gives us this true insight, and reveals to us other details of this time period. It completely changed my perspective on what people were able to do at the time."