This structure is called the Markets of Trajan. It is located in Rome on the Quirinal Hill and looks out over the forum. Apollodorus of Athens had it built to house both stores and offices. It was made from concrete, and its architect was a master of designing in this medium.
The first picture gives an aerial view of the Markets of Trajan. These markets resemble a modern day shopping mall. The second picture is of what is known as the Via Biberatica. This portion of the market is interesting because it is one of the first examples of using exposed brick as a design feature. Exposed brick was beginning to be recognized as an aesthetically pleasing building material rather than just a more economically logical way to build. The shops of this building were stacked on different levels. They opened out onto paved roads that were further up the hill, or onto a magnificent indoor market located even higher up the hill.
The third and fourth pictures are of the upper floor shops. These shops were illuminated by skylights. These skylights were also able to illuminate the shops on the ground floor of the market through sophisticated “groin vaults.” These groin vaults had been used in earlier constructions, but never with as much elegance or effectiveness. These rooms had previously only been lit by torches, but now the natural light was able to reach them. This brought a new sense of edginess and distinctness to Roman architecture.
Kleiner, Fred S. A History of Roman Art. Boston, MA: Wadsworth, 2007.