Star Forts or Bastion Forts

The perfect lines and angles of these star forts would have taken serious engineering, and to even excavate would have taken quite a lengthy time. Simple people of the time, I think not. Doesn’t mean this is all Tartarian, we have to be careful not to be led down a false path. Tartaria was real, but in my opinion more a free trade nation with many other nations in knowledge back and forth with one another. There were all kinds of knowledge around through different periods of time in history from what we can see. What do you think? 🤔