In the dome of the Pantheon in Rome, several construction techniques were used to allow such a bold construction to stand. One concerns the composition of the concrete (in this case, non-reinforced concrete) with different densities throughout the structure. Closer to the top, lighter stones were used in the mixture, reducing the dome's weight retaining the solidity of the base. Another technique was the inclusion of “coffers”, which are nothing more than subtractions in the concrete, reducing the weight of the dome while maintaining a cross section sufficiently robust to support its own weight. Built almost 1,900 years ago, this building still surprises us with the genius of the solutions. Using a quantity of materials just high enough to fulfill its primary function, and creating intelligent structures as a result, is just one of the lessons that this building provides.
