The Troy archaeological site has nine main layers, but they’re not always easy to separate. The ravages of time, earthquakes, fire, conquest, and other forces have muddled them together. Then how can it be said with any certainty that there ARE different layers, representing different civilizations? Different architectural styles offer clues. From the simple brick walls of Troy I (first photo, center), to the famous ramp of Troy II (second photo), to the ashlar (shaped stone) walls of Troy VI (left of third photo; fourth photo), the differences are striking!