They Had to Censor the Archaeologists
Great Zimbabwe's attribution was settled by the 1930s, and a modern state spent decades suppressing it. The chain was intact and the register was falsified, which is harder to repair than a fire.
There is a ruined city in southern Africa built of dressed granite, without mortar, its outer wall eleven metres high and five metres thick at the base, enclosing an interior of passages and platforms and a conical tower whose purpose nobody has settled.
It covers about seven hundred hectares. At its height, in the fourteenth century, perhaps eighteen thousand people lived there. It traded with the Swahili coast, and Chinese celadon and Persian glass have come out of the ground inside it.
When Europeans encountered Great Zimbabwe, they decided Africans could not have built it.
Phoenicians, then. Or the Queen of Sheba. Or Arabs, or some lost white race, or anyone at all, as long as it was not the people who lived there and whose descendants were standing beside the archaeologists saying, without any doubt at all, that their ancestors had built it.
The interesting part is not the initial error. Nineteenth-century Europeans got a great many things wrong about Africa and their reasons are not mysterious.