Archaeology Archaeology is difficult and fragmentary: sea-level rise, deliberate demolition of
furnaces, and repeated breakage of containers obscure direct traces. Evidence for marine salt making in western Europe reaches back to the
5th millennium BCE, where seasonal coastal
lagoons behind low sandy–silty shores likely served as proto-salterns that pre-concentrated brine before heating.
In China In China, archaeological and chemical analyses at Zhongba (
Three Gorges) demonstrate significant salt production by the first millennium BCE, with indications of earlier activity and brine-boiling as a primary technique. On the north China coast (southern
Laizhou Bay,
Shandong), late Neolithic through Shang–Zhou saltmaking sites (e.g., Shuangwangcheng, Nanheya) show sea-salt manufacture adapted to coastal flooding and
Holocene shoreline change. Multi-proxy evidence further reconstructs prehistoric sea-salt manufacture on the East China coast as an adaptation strategy to coastal flooding.
In India In India, coastal settlements on the Saurashtra–Gulf of Khambhat littoral show direct archaeological evidence for sea-salt manufacture: the Harappan site of Padri (Kerala-no-dhoro) is interpreted as a specialised salt-producing centre in the Mature Harappan period (ca. 2200–2000 BCE). A geoarchaeological synthesis notes that Padri's economy “depended on salt manufacturing” in a stable estuarine setting close to present sea level.
In Mesopotamia and Sumer In
Mesopotamia (including
Sumer), cuneiform sources attest salt as
Sumerian mun (sign MUN) and
Akkadian milḫu (salt). Procurement drew mainly on natural salines and brines of the alluvial plain and marshlands; the direct archaeological visibility of purpose-built evaporation complexes is limited.
In America At
El Salado (central
Veracruz), salt production shows two major occupational phases: an Early Formative phase (ca. 1400–1000 BCE) and a Late Classic phase (ca. AD 650–1000), identified through stratified features and residues associated with brine evaporation and salt making.
Marine salterns in antiquity Across the classical civilizations of the Mediterranean, the ancient Middle East, India and Han China, antiquity transformed salt use less through new technology than through administration and literacy: conservative production know-how persisted while political (west) and bureaucratic (east) management, enabled by classical literate elites, widened output, distribution and consumption. Within this framework, marine salterns took on greater importance: sea-salt exploitation expanded, waterborne transport increasingly displaced overland routes, and by about AD 500 sea salt supplied the larger share of salt consumption—no longer a luxury but a staple closely tied to fish processing. By
classical antiquity, extensive marine salterns (salinae) operated around the Mediterranean.
Seawater was channelled by gravity into connected, shallow evaporation ponds where brine concentration increased stepwise before crystallisation and harvest. Across the ancient Near East—including
Phoenicia,
Egypt,
Mesopotamia and
Israel—salt held ritual, symbolic and legal significance: it was prescribed for offerings at the
Jerusalem Temple; invoked in “covenants of salt” and other treaty formulae; used to curse conquered lands by salting the soil; and, in the Second Temple period, supplied to the Temple as a tax-free ration by imperial rulers. Rabbinic texts describe substantial salt usage and a dedicated storehouse for Temple sacrifices, while early Christian writings employ salt as a moral metaphor (“salt of the earth”; speech “seasoned with salt”). Some traditions also linked salt to fertility and to Aphrodite. Where conditions allowed, salt-evaporation ponds were laid out in sheltered coastal lagoons and low-energy shorelines, using networks of shallow, graded basins linked by
canals and
sluices to concentrate seawater by solar evaporation before
crystallization and harvest.
Marine salterns in middle-age On the French
Atlantic seaboard (
Guérande–
Batz, the Baie de
Bourgneuf/
Marais breton, and
Saintonge/
Brouage), purpose-built solar saltern landscapes took shape from the early Middle Ages. In the Guérande basin, marsh-based pond systems are securely attested by the 9th century (with earlier know-how) and became the dominant mode of production. In Saintonge/Brouage, sheltered lagoonal settings were engineered into étier-fed, graded ponds. The 1478 rent survey for the prévôté d’Hiers records renewed exploitation and organisation in the Saintonge marshes. Studies of distribution and river/coastal routes show Atlantic “bay salt” circulating widely from Merovingian/Carolingian times toward northern France and the British Isles. Outside France, medieval salterns are widely attested: in England, the Domesday Book (1086) records over 1,195 “salinae,” mostly on the south and east coasts. In Portugal, a 959 donation charter by Countess Mumadona Dias mentions lands “in Alavario et salinas” at Aveiro, indicating early-medieval salt pans on the Ria de Aveiro.
From early modern reorganization to industrialization After the Middle Ages, European saltmaking saw both the expansion of coastal solar salterns and the rationalization of inland brine works. In the northern Adriatic, the Piran/Sečovlje system was reorganised under Venetian rule (regular sequences of evaporation and crystallisation basins) and, during a 15th-century wave of salt-pan destructions elsewhere, Piran's pans remained active and entered a prolonged “golden age.” ==Gallery==