The Romans were the first to fully exploit arched construction. They also mixed lime, water and volcanic ash and called it 'pozzolana.' The Roman civil engineer, Vitruvius, wrote about four types of concrete; black, red, grey, and white.
Understanding how remarkable this new building material was, the Romans employed its waterproof qualities in constructing their port at Cosa in the later second and early first centuries B.C. Amazingly, three of its concrete piers still stand as a testament to the Roman's engineering and the durability of concrete.
See, concrete is more fascinating than you thought. Isn't it?