A five-acre Roman-era pottery factory with 21 kilns surfaced in northern France

French archaeologists have uncovered a Roman-era pottery works at Sermaize, in the Oise department of northern France, that covers 20,000 square metres, or 2 hectares, and holds 21 kilns. The National Institute for Preventive Archaeological Research, known as Inrap, calls the site an exceptional ceramic production workshop, and its scientific lead is Louis Florin.

The workshop was in use from the first century B.C. to the third century A.D., and the layout shows the whole sequence of the trade in one place: pits where clay was dug, basins where it was prepared, wheels where pots were shaped, and kilns where they were fired. The kiln total is a counted set, and Inrap breaks it down by design.

Two hectares of clay pits, basins and wheels

The site figure in Inrap’s own announcement, published on September 30, 2026 and updated on October 1, is a surface of 20,000 square metres. Archaeology magazine, in its October 6 item, describes the same ground as a five-acre site, which is the same area converted into acres. Inrap’s figure is the one used here.

Within that area sits a clay extraction zone of about 2,500 square metres with roughly fifty pits cut into it, along with chalk quarry pits at the edge of the workshop. The excavators also recorded, in Inrap’s tally, 20 flat-bottomed basins, 14 groups of potter’s wheels and about ten cellars. According to Inrap, three of the wheel groups held a single wheel and eleven held between two and six. The magazine adds hearths, ovens, wells, food waste and storage jars to the finds, and says the workshop stood on the Agrippa Road, one of the Roman routes that carried the finished pots away.

Twenty-one kilns in three designs

The kiln count is a tally of three designs, and Inrap gives each its number. Sixteen are single-flue kilns with a suspended floor: twelve dating to the first century A.D., and four contemporary with the mid-second to mid-third century phase. Two are double-flue kilns with cross-shaped walls supporting the floor, dated to the late first to early second century A.D. Three are double-flue kilns with a central wall, two of them with lateral supports, dated from the mid-second to mid-third century A.D.

That sums to 21, and it shows a workshop that kept changing its furnaces over roughly three centuries instead of building one design and repeating it. Greek Reporter’s account of the dig notes that the later double-chamber kilns were used for dark ceramics, matching Inrap’s description of dark common ware from the second century onward.

Terra nigra imitations and dark common ware

Inrap lists the products by period, and the sequence reads like a change in fashion as much as in technique. In the first century the potters made fine black-surfaced ware inspired by Italic terra nigra, mica-gilded beakers and shell-tempered cooking ware. From the second century the output shifted to dark common ware, a plainer product for everyday households, fired in the double-flue kilns of the later phase. Archaeology Newsroom adds that the later kilns of the second and third centuries made dark-coloured ceramics, which fits that shift. Archaeology magazine singles out storage jars among the finished vessels.

The grid layout is the detail Archaeology magazine stresses: it calls the discovery a complete Roman pottery workshop laid out on a grid, with areas for preparing clay and shaping pots on wheels set beside the kilns. That arrangement is why the site is read as a mass-production line and not as a scatter of household kilns, since each stage of the work has its own identifiable space inside the same compound.

The same Greek Reporter piece says the site became an organised production centre in the second half of the first century B.C., and credits photographs to Florin, Sabrina Sarrazin and Victor Viquesnel-Schlosser, all of Inrap.

A dig tied to a canal

The excavation was triggered by development work. Inrap states that the project is the one carried out by the Société Canal Seine-Nord Europe, with scientific control by the regional archaeology service of the Hauts-de-France cultural affairs directorate. The company’s planned Seine-Nord Europe canal is a large-gauge waterway meant to run 107 kilometres from Compiègne, in the Oise, to Aubencheul-au-Bac, in the Nord, and Archaeology Newsroom’s write-up confirms that Inrap excavated the site ahead of construction for that canal.

Archaeology Newsroom also reports six stone pivots and 13 flint pottery tools among the equipment recovered, small items that anchor the larger numbers in the daily labour of the potters who worked there, and that sit alongside the wheels, basins and cellars as evidence of a settled, specialised trade.

Neither Inrap’s page nor the magazine item gives dates for the fieldwork, and Inrap includes no direct quotation from Florin. What the record does establish is the set of figures above: 20,000 square metres, 21 kilns split 12, 4, 2 and 3 across three designs, about fifty clay pits, and an occupation from the first century B.C. to the third century A.D.

This article was produced with the assistance of AI and reviewed by Morning Overview editors prior to publication.

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