Macellum of Pozzuoli

The Macellum of Pozzuoli (Italian: Macellum di Pozzuoli) was the macellum or market building of the Roman colony of Puteoli, now the city of Pozzuoli in southern Italy. When first excavated in the 18th century, the discovery of a statue of Serapis led to the building being misidentified as the city's serapeum or Temple of Serapis.

A band of borings or Gastrochaenolites left by marine Lithophaga bivalve molluscs on three standing marble columns indicated that these columns had remained upright over centuries while the site sank below sea level, then re-emerged. This puzzling feature was the subject of debate in early geology, and eventually led to the identification of bradyseism in the area, showing that the Earth's crust could be subject to gradual movement without destructive earthquakes.

The city of Dicearchia, founded by Greek refugees escaping dictatorship on Samos, was integrated into the Roman Empire as the city of Puteoli in 194 BC. The macellum or food market was built between the late first and early second century AD, and restored during the third century AD under the Severan dynasty.

The building was in the form of an arcaded square courtyard, surrounded by two-storey buildings. Shops lined the marble floored colonnade forming an arcade with 34 grey granite columns. The main entrance and vestibule were positioned on a main axis, which lined up across a tholos in the centre of the square to the exedra for worship which had a portico formed by four large cipollino marble columns. The exedra had three niches for statues of divinities giving protection to the market, including the sculpture of Serapis. The tholos in the centre of the square was a circular building standing on a podium reached by four symmetrically placed access stairways, with sixteen African marble columns supporting a domed vault. Marine animals decorated friezes around the base of the tholos. The courtyard had four secondary entrances on its longer sides, with latrines in the corners of the colonnade and four (probable) tabernae with their own external entrances as well as access from the arcade.

...
Wikipedia