The longest graffiti mural in Africa resides in Benin!   It pays homage to Benin’s rich history of the ancient empire of Dahomey. The length of the mural is 940 meters or over 3000 feet.

https://www.africanews.com/2021/06/15/benin-s-world-record-holding-graffiti-mural-celebrates-dahomey-kingdom/