Have you researched the Kano city walls? It’s a great piece of architecture built by the Kano people during medieval times. It had 12 city gates.
“The ancient Kano city wals were built in order to provide security to the growing population. The foundation for the construction of the wall was laid by Sakri Gijimasu from 1095 - 1134 and was completed in the middle of 14th Century during the reign of Zamnagawa.“-UNESCO
“This impressive work of military engineering was then some 11 or 12 miles in length, 40 feet thick at the base and varying from 30 to 50 feet in height. A broad rampart walk ran behind the 4-foot thick loop-holed crest of the wall which was pierced by 13 gates, the whole further strengthened by a deep ditch.“
The Lost Cities of Africa book has lots of good information like this in it. I have found that many races and cultures across the world has lost or hidden architecture that seemed to have been built or designed by the “older” types of gentile races, different than the gentile products we have today. And when I say that, less advanced than today.