Roman Ruins of Troia: A Roman Fish-Salting and Trade Settlement in Portugal
Site at a Glance
- Rating
- 4.2
- Popularity
- Low
- Country
- Portugal
- Primary era
- Classical
- External website
- Open
- Eras represented
- Classical, Medieval
- Civilizations
- Roman
- Site type
- Economic
- Remains
- Production Complex
On this page13 sections
History
The Roman Ruins of Troia are an archaeological site at Tróia in Portugal, on the northwest side of the Troia Peninsula opposite Setúbal. Built and used by the Romans from the first to the sixth century CE, the settlement formed part of the territory of Salacia, the Roman city corresponding to present-day Alcácer do Sal. Its main purpose was the processing, salting, and export of fish and fish sauces, including garum, a fermented fish sauce preserved with salt and transported in ceramic containers.
A Coastal Production Centre
The settlement occupied a dune peninsula between the Sado estuary and the Atlantic Ocean. Fish were plentiful, salt was readily available, and amphorae could be supplied from pottery centres on the opposite bank of the Sado. These conditions supported an industrial complex that produced salted and pickled fish and sauces for markets across the Roman Empire. The peninsula may have been an island during the Roman period. Some scholars have connected it with Ácala, an island mentioned in Ora Maritima by the fourth-century Latin writer Avienus, but this identification remains unconfirmed by archaeological evidence.
Later References and Excavation
Sixteenth-century humanists Gaspar Barreiros and André de Resende referred to the ruins, although they appear to have mistaken them for Cetóbriga, the ancient settlement associated with present-day Setúbal. Later writers also described the remains. The first known excavations took place in the second half of the eighteenth century under the patronage of Princess Maria I, who later became queen of Portugal. Roman houses uncovered during this work gave the area its name, the Houses of the Princess.
Archaeological investigation gained fresh momentum in 1850 after the creation of the Lusitanian Archaeological Society. Excavations in the Houses of the Princess uncovered painted walls and mosaic floors, but these features have since disappeared. Campaigns between 1948 and 1967 explored the baths, fish-salting workshops, burial areas, and early Christian basilica. Later work, including investigations supervised by the archaeologist Inês Vaz Pinto, has continued to identify remains and examine ceramics, animal remains, and metal objects.
The ruins have been classified as a Portuguese National Monument since 1910 and appear on Portugal’s tentative list for UNESCO World Heritage designation. The Portuguese Republic owns the site, which has a cultural function. In 2021, the archaeological team and the restaurant Can the Can produced garum in one of the ancient salting tanks for the first time in more than fifteen centuries. The planned production of approximately 200 to 300 litres connected a modern project with the settlement’s ancient manufacturing tradition.
Remains
The surviving site extends across a dune peninsula and contains industrial, residential, funerary, thermal, hydraulic, and early Christian structures dating from the first to the sixth century CE. Its physical layout is dominated by fish-processing workshops, while houses, baths, burial areas, water installations, and the basilica reveal the varied activities that surrounded the production centre.
Fish-Salting Workshops
Processing Complex
Twenty fish-salting workshops have been identified, although not all have been fully excavated. Together they contain 182 processing tanks, known as cetariae, arranged around central courtyards. The largest workshop covered more than 1,000 square metres and had 19 tanks. The smallest covered 135 square metres and contained nine smaller tanks, probably intended for preparing different products. Their number and concentration point to production on a large scale for export, although the precise quantities made in the tanks are unknown.
Containers and Storage Vessels
The workshops processed salted and pickled fish as well as fish sauces. Amphorae, large ceramic transport containers for liquids and processed foods, carried these products. Many came from pottery centres on the right bank of the Sado, including Abul, a former Phoenician trading settlement. Finds from the complex include amphorae, dolia, which were larger storage vessels, and terra sigillata pottery.
Residential and Bathing Areas
Houses of the Princess
The residential areas included dwellings linked with workers and factory owners. The Houses of the Princess contained both ground-floor and upper-floor homes. Painted wall decoration and mosaic floors found during nineteenth-century excavations formed part of these residences before they disappeared.
Thermal Baths
Excavated in 1956, the thermal baths covered 450 square metres. Their rooms included a vestibule or changing area, a cold-water room and pool called a frigidarium, a warm room or tepidarium, a hot room or caldarium, additional pools, and an exercise room. An underground heating system, or hypocaust, warmed the complex. A furnace sent hot air beneath raised floors supported by small pillars, and one pool retains mosaic remains. A reservoir near a spring supplied water to the bathing rooms.
Burial and Religious Structures
Mausoleum and Burial Areas
Four burial zones form part of the site, including several necropolises and a mausoleum. Built beside Workshop 2 during the first half of the third century, the mausoleum contained wall niches for urns holding cremated remains and tombs set into the floor for inhumations. A burial area on a sand dune behind it probably dates from the fifth century. Its graves used stones and bricks, with most bodies placed with their heads toward the northwest and feet toward the southeast. One priest was buried in the opposite orientation.
Columbarium and Basilica
A columbarium, a structure containing niches for funerary urns, is also preserved. The site includes a Roman water wheel known as a rota aquaria and the remains of an early Christian basilica. Dating from the late fourth or early fifth century, the basilica was built over a fish-salting workshop that had been abandoned.
A marble relief dedicated to Mithra was found in the basilica. Mithra was a deity worshipped in the Roman mystery cult of Mithraism, a religious tradition associated with initiation ceremonies and the protection of cosmic order. The relief points to a pre-Christian religious association at the location before construction of the early Christian church.
