The Great Zimbabwe was

Great Zimbabwe was a medieval African city known for its large circular wall and tower. It was part of a wealthy African trading empire that controlled much of the East African coast from the 11th to the 15th centuries C.E.

Explanation:

Great Zimbabwe: African City of Stone. The ancestors of the Shona people built Great Zimbabwe, which flourished between the 11th and 15th centuries A.D. Great Zimbabwe was a 720-hectare (1,779 acres) city that flourished between roughly the 10th and 15th centuries A.D.

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