Or it could have started by building a kill pit at the end of a natural ridge/wall/stream, and using dozens of men to force the antelopes along the path to the

Or it could have started by building a kill pit at the end of a natural ridge/wall/stream, and using dozens of men to force the antelopes along the path to the pit. Then someone said "wait, if we build another barrier on the other side, we could do this with fewer men... But either way, I doubt they were just chasing antelopes across flat land and one dude said "Eureka! I've got it!"