Fordongianus: Where Roman Waters Still Flow from the Earth

The river that boils in forgotten Sardinia

On the banks of the Tirso river, in the heart of central-western Sardinia, water bursts from the rock at 54°C and tumbles into the river in a plume of steam visible from far away. Fordongianus — ancient Forum Traiani of the Romans — is a small town of three thousand souls that preserves the most important Roman thermal complex in Sardinia, a place where hot water has drawn civilizations for over two thousand years.

The Roman name Forum Traiani tells us it was Emperor Trajan, in the first century AD, who drove the colonization of this strategic site, on the border between the Romanized coastal Sardinia and the inland territories inhabited by the Barbaricini. But the springs were known long before: the Nuragic people frequented them, and traces of water cults have been found in the area. For the Romans, Forum Traiani was both a military and a thermal outpost — the two functions often coinciding — where soldiers stationed in the province could heal and rest.

The thermal archaeological site

The Roman thermal complex extends along the left bank of the Tirso, arranged across multiple levels. The most imposing structure is the great rectangular pool from the first century AD, fed directly by the hot spring. The walls in opus vittatum — blocks of red trachyte alternating with courses of brick — are perfectly preserved, holding a red-orange hue that contrasts sharply with the green of the riparian vegetation.

The water is classified as hyperthermal fluoride-rich, with a spring temperature between 54°C and 56°C. It is clear, almost odourless compared to sulphurous thermal waters, with a faint mineral taste. Its therapeutic properties are recognised for rheumatic, dermatological, and respiratory ailments. A small modern thermal facility has been built alongside the archaeological site, offering pools and treatments that use the same water from the ancient spring.

The red trachyte

One of Fordongianus's most distinctive features is the stone from which the entire historic centre is built: red trachyte, quarried locally, which gives the borgo a look unlike anywhere else in Sardinia. The Casa Aragonese, overlooking the Tirso, is the most photographed building: a 16th–17th century noble residence built entirely in trachyte, with an inner courtyard that hosts cultural events. The contrast between the red stone, the green river and the white plume of steam is one of the most singular panoramas on the island.

Practical information

Access and costs

The archaeological thermal site is open to visitors for a modest fee, covering the Roman ruins and the spring. The small modern thermal facility, managed separately, offers baths and treatments at accessible prices. Along the river, outside the fenced site, hot water mingles with the Tirso creating natural pools where you can bathe for free — the temperature is milder here, around 36–38°C, and the experience is wilder.

Getting there

Fordongianus lies about 30 km from Oristano, along the SP44 that follows the Tirso valley (coordinates 39.9948°N, 8.8098°E). From Oristano it takes half an hour, from Cagliari an hour and a half. Parking is available in the village, a short walk from the thermal site. Public transport connections are infrequent: a car is practically essential.

When to go

Inland Sardinia is beautiful in every season, but the best months for the thermal baths are spring (March–May) and autumn (September–November). Winter can be cold in the hinterland, but the contrast with the hot water makes the experience all the more intense. Summer is hot and dry — the thermal bath loses some of its charm when the air temperature climbs above 35°C.

What to bring

• Swimsuit and towel for the pools along the river
• Water shoes for the Tirso riverbed (stony bottom)
• Sun protection in spring and summer
• Camera for the Roman ruins and the red trachyte
• Insect repellent on summer evenings (the river attracts mosquitoes)

Exploring inland Sardinia

Fordongianus is a gateway to the most authentic and least visited Sardinia. To the north, the road climbs the Tirso valley toward Lake Omodeo, the largest artificial reservoir in Europe at the time of its construction in 1924, ringed by bare hills and isolated nuraghi. To the east, the road toward Samugheo crosses a rugged, wild landscape where the weaving tradition is still alive in workshops that produce Sardinian rugs using age-old techniques.

The MURATS Ethnographic Museum in Samugheo is worth a visit for its collection of traditional textiles. To the south, the archaeological site of Santa Cristina — with its perfectly preserved Nuragic sacred well — is one of the most evocative prehistoric sites in Sardinia. For food, in Fordongianus the restaurant Sa Parrera serves inland Sardinian cuisine: culurgiones, malloreddus, porceddu, accompanied by wines from the Mandrolisai region.

Water that binds the millennia

Fordongianus is a place where Roman thermalism, Sardinian landscape and provincial tranquillity converge in a rare experience. No crowds, no superfluous luxury: only hot water emerging from the earth as it has for millennia, red stones soaking up the sun, and the Tirso flowing slowly toward the sea. This is the Sardinia that never appears in brochures — the kind you only discover by losing yourself on the inland roads, far from the coast.