View looking south at the niche that served as a temple on the north side of the macellum. Here there was a temple for the Imperial Cult (aka Emperor worship). A statue of the Egyptian deity Serapis was found here and thus this area is sometimes called the Temple of Serapis.
Please note the water on the floor, this is because the market sits on top of the caldera of a volcano and it has risen and sunk through the ages. This phenomenon is called "Bradyseism."
The three columns at the entrance to the niche (exedra) were at times almost covered with water because the surface of the ground sank and seawater filled the area. At times 19.5 feet of the columns were under water—due to sinking! Between 1982 and 1994 the land rose 5.6 feet! And because of a fear that the underlying volcano might explode, 30,000 people were evacuated from Pozzuoli! In 2017, when this picture was taken, very little of the Macellum was under water.
The blue on the horizon is where the harbor of Puteoli is located.