Macellum of Pozzuoli

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.

[3] It attracted visits from antiquarians, among them William Hamilton whose Campi Phlegraei of 1776 showed a distant view of the buildings dry above sea level,[5] and John Soane who "Went to the Temple of Jupiter Serapis" on 1 January 1779 and made rough sketches, as well as a plan of the complex, possibly copied from another drawing.

He argued that the evidence did not support the suggestion of falling sea levels worldwide, but thought seismic explanations were inadequate as earthquakes notoriously shook buildings until they collapsed, and the columns were still standing.

[5] In 1802, John Playfair, in his Illustrations of the Huttonian Theory of the Earth, used Breislak's descriptions to support James Hutton's ideas of slow changes, attributing the differing heights of water around the columns to "oscillations" in the level of the land.

[3] The excavations lost stratigraphic information in the deposits which had buried the building, but the band of borings or gastrochaenolites left by marine Lithophaga bivalves on the three standing marble columns provided a good record of relative sea level variation.

In 1820, he published a study of his Ricerche sul Tempio di Serapide, in Puzzuoli, including an illustration based on a drawing by John Izard Middleton showing the three columns with the bands affected by molluscs.

The first volume of Veränderungen der Erdoberfläche by Karl Ernst Adolf von Hoff, published in 1822, included an account of the ruins as demonstrating relative changes in land and sea level.

In Goethe's 1823 Architektonisch-naturhistorisches Problem, he suggested that silt or ash had partially buried the columns and at the same time held back water forming a lagoon above sea level.

[5] In his 1826 book A Description of Active and Extinct Volcanoes, Charles Daubeny dismissed the implied sinking of the land by 30 feet (9.1 m) followed by almost as great a rise as unlikely, since "it is probable that not a single pillar of the temple would now retain its erect posture to attest the reality of these convulsions".

Lyell wrote "That buildings should have been submerged, and afterwards upheaved, without being entirely reduced to a heap of ruins, will appear no anomaly, when we recollect that in the year 1819, when the delta of the Indus sank down, the houses within the fort of Sindree subsided beneath the waves without being overthrown."