The infamous king, Herod the Great (72-4 BCE), known mostly for his brutality (cf. Matthew 2:16-18), was also admired for his building prowess in the ancient Mediterranean world. His construction projects included the Temple Mount in Jerusalem, the fortress of Masada, the palaces at Jericho and Herodium, and the sprawling seaside metropolis of Caesarea Maritima (where Paul was once imprisoned; see Acts 25).
One of the misconceptions about ancient culture is that they were “less advanced” than we are today, from their thoughts to their infrastructure. This, however, is simply a stereotype. All of Herod’s building projects defy this notion, but one of many astonishing examples that demonstrate the genius of ancient engineering was his building of Caesarea Maritima. Roman engineers discovered the secret of hydraulic concrete (concrete that still hardens underwater) only a few years before Herod built Caesarea. How about that for thought and ingenuity?
Famous architect, engineer, and author Vitruvius’ (a.k.a. Marcus Vitruvius Pollio) published De architectua in 25 BCE — an architectural text that describes this genius discovery. A special sand called pozzolana was used to aid in the hardening of the concrete underwater. Vitruvius wrote, “There is also a kind of powder… found in the country belonging to the towns about Mount Vesuvius. This substance, when mixed with lime and rubble, not only lends strength to buildings of other kinds, but even when piers of it are constructed in the sea, they set hard underwater.”
Herod’s builders were resourceful. When they learned of this, they utilized hydraulic concrete to build Caesarea’s harbor. Two large blocks of concrete were explored in the harbor in 1982 (thanks to studies in underwater archaeology). The larger block measured 40 x 50’, 5’ high, containing 10,000 cubic feet of concrete; the second block was only slightly smaller, and remnants of the wood frame around it had also been preserved. It was later determined that these blocks were the foundations for towers that stood at the entrance of the harbor. With stunning feats of ingenuity such as this, we can learn a lot about the genius of ancient minds if we dig…or swim…a little deeper!