Footnote 3 – News from the Field: Herod’s Harbor Construction Recovered Underwater

The term “Roman concrete” is also used to refer to opus reticulatum walls (see “Herod’s Family Tomb in Jerusalem”), walls built with uniformly cut small stones laid in a diagonal or other pattern. The concrete that was the core of opus reticulatum walls had the same composition as the concrete used in the breakwaters at Caesarea.

When used with respect to opus reticulatum,“Roman concrete” refers to the entire wall including stones and binding concrete; but as it is used to describe the material poured into forms at Caesarea, Roman concrete refers to the concrete blocks.