Wood, bone, stone, and earth are some of the materials, which formed the structures of the Roman Empire. Certain structures were made possible by the character of the land upon which these structures are built. Romans mixed powdered limestone, volcanic ash found from Mount Vesuvius, and water to make a cement paste. A volcanic peninsula with stone aggregates and conglomerates containing crystalline material will produce material, which weathers differently from soft, sedimentary rock and silt. With the discovery of cement paste, structures could be built with irregular shaped stones and have the binder fill the voids to create a solid structure. The cement gains strength as it hydrates, thus creating a stronger bond over time. With the fall of the west Roman Empire and the rise of the Byzans, this knowledge was mostly lost except to the catholic monks, who were among the few who could read Vitruvius’ Latin and make use of the concrete paste. That is one of the reasons that the concrete Pantheon of Rome could last for 1,850 years, and why the thatched farmhouses of Holland sketched by Rembrandt have long since decayed.