Pre-colonial African techniques

pre-colonial African technologies that would surprise most people part one the medieval Nigerian city of benin's wall was built to a scale comparable with the Great Wall of China there was a vast system of defensive Walling totaling 10 000 miles even before the full extent of the city Walling had become apparent the Guinness Book of Records carried an entry in the 1974 Edition that described the city as the largest Earthworks in the world carried out prior to the mechanical era two the residents of the Ghanaian emperor in 1116 A.D was a well-built castle thoroughly fortified decorated inside with sculptures and pictures and having glass windows this is the first recognized indigenous sub-Saharan African Glass Technology dated to early 2nd Millennium A.D or earlier three between the 14th and 17th centuries the adjourn sultanate centered in modern-day Somalia practiced Hydraulic Engineering and developed new systems for agriculture and Taxation which continued to be used in parts of the Horn of Africa as late as the 19th century