 In this characteristic environment, the ancient Greek architects constructed buildings that were marked by precision of detail.The gleaming marble surfaces were smooth, curved, fluted, or ornately sculpted to reflect the sun, cast graded shadows and change in colour with the ever-changing light of day.Historians divide ancient Greek civilization into two eras, the Hellenic period (from around 900 BC to the death of Alexander the Great in 323 BC), and the Hellenistic period (323 BC to 30 AD).