Macellum of Puteoli

The Macellum of Pozzuoli, in the Roman colony of Puteoli (modern Pozzuoli, southern Italy), was the city’s market building. When first excavated in the 18th century, a statue of the god Serapis was found, leading to its misidentification as a Temple of Serapis. The name has stuck, though it is simply a commercial structure. Its most intriguing feature is the three standing marble columns, pitted by marine molluscs near the base, which provide clear evidence of changing sea levels over the centuries. This phenomenon, noted by geologists, makes the site a curious monument to both Roman commerce and the slow, inexorable movements of the earth.

Description via source. Coordinates and heritage data from the Atika atlas.