Introduction
Welcome to Martigny, known to the Romans as Octodurus and later as Forum Claudii Vallensium. This small Valais town at the great bend of the Rhone River holds one of the most significant concentrations of Roman archaeological remains in Switzerland. For centuries, Martigny was a major crossroads of the ancient world, the gateway to the Great St. Bernard Pass and the route between the Roman provinces of Gaul and Italy.
Today, Martigny is perhaps best known for the Fondation Pierre Gianadda, one of Europe's finest private art museums. But beneath and around the modern town, the bones of a Roman city lie remarkably well preserved. This tour connects the principal Roman sites, from the amphitheatre to the temple district, and places them in the context of the extraordinary Alpine crossing that gave Octodurus its strategic importance.
The Great St. Bernard Pass, which rises to 2,469 metres above sea level about 35 kilometres south of Martigny, has been one of the most important Alpine crossings for at least three thousand years. Celtic traders, Roman legions, medieval pilgrims, Napoleon's armies, and modern motorists have all passed through Martigny on their way to or from this storied pass. The town's identity has always been shaped by its position at this critical junction of routes.
Stop 1: Martigny Station and the Rhone Bend — 46.1019, 7.0735
Exit the station and look south toward the mountains. You are standing at one of the most geographically significant points in the Alps. Here, the Rhone River makes its dramatic ninety-degree turn, changing from a roughly east-west course to a north-south one as it heads toward Lake Geneva. This bend is not a geological coincidence but the result of two different valley systems meeting at right angles: the main Rhone trench running east-west and the Drance valley running south toward the Great St. Bernard.
It was this junction of valleys that made Octodurus strategically vital. Whoever controlled this crossroads controlled access to the most important Alpine pass between the Swiss Mittelland and the Po Valley. The Celtic Veragri tribe, who inhabited this area before the Romans, understood this perfectly. Their settlement on the valley floor was one of the most important Celtic towns in the western Alps.
The Romans arrived in force in 57 BC, when Julius Caesar sent his general Servius Galba with the Twelfth Legion to secure the Great St. Bernard route. The campaign did not go smoothly. Galba established a winter camp near Octodurus, but the Veragri attacked in force, and the legion barely escaped destruction. It was not until the reign of Emperor Claudius, around 47 AD, that the Romans permanently established their town here, renaming it Forum Claudii Vallensium, the Market of Claudius in the Valais.
Walk south along the Rue du Forum, heading toward the old part of town. The Roman city lay beneath your feet.
Stop 2: Roman Temple District (Temenos) — 46.0994, 7.0759
You have reached one of the most important Roman religious sites in Switzerland. The temenos, or sacred precinct, of Roman Martigny was discovered during construction work in 1976 and has been partially excavated and conserved.
The remains visible today include the foundations of a Gallo-Roman temple, identifiable by its characteristic plan: a square central cella, or shrine room, surrounded by an ambulatory corridor. This plan, known as a fanum, is distinctive to the Celtic-influenced provinces of the Roman Empire and differs from the classical temples of Rome and the Mediterranean. It represents a fusion of Celtic and Roman religious practice, where indigenous deities were worshipped in buildings that combined local traditions with Roman construction techniques.
The principal deity worshipped here may have been Mercury, the Roman god of commerce and travellers, who was commonly venerated at crossroads and along trade routes. The association is logical for a town that owed its existence to the traffic passing through it. Inscriptions found at the site dedicate offerings to Mercury and to the Genius of the Market, suggesting that religion and commerce were closely intertwined.
Near the temple foundations, archaeologists found bronze statuettes, ceramic oil lamps, coins, and fragments of monumental sculpture. Many of these objects are now displayed at the Fondation Pierre Gianadda, which we will visit later in this tour. The finds suggest that the temenos was an active place of worship from the first century AD through at least the fourth century, when Christianity began to replace the old religions.
Stop 3: The Insulae — Residential Quarter — 46.0990, 7.0748
Walking west from the temple district, you pass through the area where the residential quarters of the Roman town have been identified through excavation. Roman urban planning was organised around insulae, rectangular blocks of buildings separated by a grid of streets. Martigny's grid has been partially traced through aerial photography and rescue excavations, revealing a town that covered approximately fifteen hectares and housed perhaps two to three thousand people at its peak.
The insulae contained a mix of housing, workshops, and shops. The ground floors of buildings facing the main streets were typically given over to commercial use, with taverns, bakeries, and craft workshops opening directly onto the sidewalk. Living quarters occupied the upper floors and the buildings' interiors. The construction was a mix of stone foundations and timber-framed upper stories, with tiled roofs.
One of the most interesting discoveries was a hypocaust system, the underfloor heating that was a standard feature of Roman domestic comfort. Hot air from a furnace was circulated beneath a raised floor, supported on small brick pillars, warming the rooms above. The presence of hypocaust heating in Martigny tells us that the Roman inhabitants were accustomed to Mediterranean standards of comfort and were willing to invest in the technology needed to maintain them in the harsh Alpine climate.
The streets between the insulae were paved with local stone and provided with drainage channels. The Romans were meticulous engineers of urban infrastructure, and even in this small provincial town, they installed running water, sewers, and public fountains. The water supply was brought from springs in the surrounding hills via an aqueduct, fragments of which have been found on the slopes above the town.
Stop 4: The Roman Amphitheatre — 46.0972, 7.0782
You have arrived at the most visually impressive Roman monument in Martigny: the amphitheatre. This elliptical arena, measuring approximately 80 metres by 65 metres, could seat an estimated six thousand spectators, a number that significantly exceeds the resident population of the town. The amphitheatre was clearly designed to serve the wider region, drawing audiences from across the Valais and perhaps from across the pass.
The structure was built in the first century AD, during the period of Martigny's greatest prosperity. It used the natural slope of the terrain on its eastern side, cutting into the hillside to create the seating tiers, while the western side was built up with massive stone walls. This technique, common in provincial Roman amphitheatres, saved enormous amounts of material and labour compared to the fully freestanding amphitheatres of Italy.
Walk into the arena through the main entrance tunnel on the north side. This is the same entrance used by gladiators, animal handlers, and condemned prisoners two thousand years ago. The tunnel is built of heavy stone blocks and retains its original vaulted ceiling. As you emerge into the open arena, imagine the noise: six thousand spectators cheering, the clash of weapons, the roar of animals.
What was performed here? Roman amphitheatres hosted a variety of spectacles. Gladiatorial combats, the most famous, pitted trained fighters against each other in bouts that were sometimes to the death but more often ended when one fighter submitted. Animal hunts, or venationes, were also popular, pitting exotic or dangerous animals against each other or against human hunters. Public executions and dramatic re-enactments of mythological stories rounded out the programme.
The amphitheatre fell into disuse in the late Roman period, probably in the fourth or fifth century, as Christianity spread and the spectacles that had filled it fell out of favour. Over the centuries, the stones were quarried for other buildings, and the arena was gradually filled with sediment. Excavation began in the early twentieth century and has continued intermittently since then. The amphitheatre is now one of the most popular cultural venues in the Valais, hosting open-air concerts and performances in summer.
Stop 5: Via the Roman Road — 46.0980, 7.0770
Leaving the amphitheatre, walk along the Rue du Forum toward the centre of the old town. You are approximately following the route of the main Roman road that ran through Octodurus. This road connected the Rhone Valley route from Lake Geneva with the Great St. Bernard Pass road to the south, making it one of the most heavily trafficked stretches of road in the Roman Alps.
Roman roads were engineering marvels, built to last and designed for military movement as well as commercial traffic. A typical Roman road was constructed in several layers: a foundation of large stones, a middle layer of compacted gravel and sand, and a surface of fitted stone slabs. The road was cambered, higher in the centre than at the edges, to shed rainwater into drainage ditches on either side. Many Roman roads in the Alps have survived beneath later road surfaces, and sections are occasionally uncovered during construction work.
The traffic on this road would have been extraordinary for a provincial town. Military units marching to and from the frontier in Germania or Britannia. Merchant convoys carrying wine, olive oil, and pottery from Italy to the north. Government couriers racing between Rome and the provinces. And ordinary travellers: pilgrims, migrants, fortune-seekers, and the occasional tourist, for the Romans invented tourism as surely as they invented concrete.
The road's importance continued long after the fall of Rome. In the early Middle Ages, it became part of the Via Francigena, the great pilgrimage route from Canterbury to Rome that brought thousands of medieval pilgrims through Martigny. In 1800, Napoleon brought his army of forty thousand men and their artillery through Martigny and over the Great St. Bernard, one of the most famous Alpine crossings in military history. A detour to the nearby Col du Grand-Saint-Bernard reveals the hospice that has been offering refuge to travellers for over a thousand years.
Stop 6: La Batiaz Castle — 46.1002, 7.0659
Looking west from the town centre, the ruined castle of La Batiaz is dramatically perched on a rocky outcrop above the Drance River. While not a Roman site, this thirteenth-century fortress tells the next chapter in Martigny's story. After the fall of Rome, the strategic value of this crossroads did not diminish, and medieval powers fought to control it just as the Romans and Celts had before them.
La Batiaz was built by the Bishops of Sion around 1260 as a stronghold to control the entrance to the Val d'Entremont and the Great St. Bernard Pass. The circular keep, which still stands to a considerable height, was a state-of-the-art military design for its era, with walls over two metres thick and a commanding view of all approaches.
The castle changed hands multiple times during the turbulent medieval history of the Valais. It was besieged, captured, burned, rebuilt, and besieged again. In 1518, it was partially dismantled by the people of Martigny themselves, who had grown weary of being controlled by the bishop's garrison. The ruin has stood open to the sky ever since, slowly being reclaimed by vegetation.
If you have the energy for the climb, the view from the keep is exceptional. You can see the full extent of the Rhone bend, the junction of the Drance valley, and the mountains that wall in this remarkable landscape on every side.
Stop 7: Old Martigny and the Episcopal Chapel — 46.0995, 7.0718
Walking back toward the centre, you pass through the streets of old Martigny, where medieval and early modern buildings stand on Roman foundations. The continuity of settlement here is remarkable. People have lived on this same patch of valley floor for at least two thousand years, building, destroying, and rebuilding in an unbroken cycle.
The small chapel of Notre-Dame de Compassion, tucked into a side street, contains some of the oldest Christian remains in the Valais. Christianity arrived in the Rhone Valley early, probably in the fourth century, brought by Roman soldiers and administrators who had converted to the new faith. The first Bishop of Octodurus is recorded in 381 AD, making this one of the oldest dioceses north of the Alps.
The transition from Roman paganism to Christianity was not always smooth. Archaeological evidence suggests that the old temples were not destroyed but gradually abandoned and repurposed. Stones from the pagan temenos were reused in early Christian buildings, creating a physical continuity between the two religions. In the crypt of the chapel, fragments of Roman sculpture are visible, incorporated into the medieval masonry as building material.
Stop 8: Fondation Pierre Gianadda — 46.0988, 7.0709
Your walk ends at one of the most remarkable cultural institutions in Switzerland. The Fondation Pierre Gianadda was created in 1978 by Leonard Gianadda, a Martigny businessman and engineer, as a memorial to his brother Pierre, who died in an aviation accident in 1976. The foundation was built on the site where the Gallo-Roman temple had been discovered, and the museum incorporates the archaeological remains into its architecture.
The Gallo-Roman Museum, in the basement of the foundation, displays the finest finds from Martigny's Roman past. The centrepiece is a magnificent bronze head of a bull, over thirty centimetres high and weighing nearly twenty kilograms, which was discovered during the foundation's construction. This remarkable sculpture, dating from the first or second century AD, is one of the finest examples of Gallo-Roman bronze work in existence.
The museum also houses a collection of Roman inscriptions, ceramics, glass, bronze statuettes, and coins. A model of the Roman town shows the layout of the insulae, the location of the forum and baths, and the relationship between the town and the amphitheatre. The display is compact but exceptionally well curated, providing a clear and vivid picture of life in a small Roman Alpine town.
Above the archaeological museum, the foundation hosts major temporary art exhibitions that have become legendary in the museum world. Exhibitions of Picasso, Monet, Renoir, Van Gogh, and Cezanne have drawn hundreds of thousands of visitors to this small Valais town. The sculpture park outside contains works by Rodin, Henry Moore, Miro, and Niki de Saint Phalle, set among ancient Roman walls and modern landscaping.
There is also an automobile museum housing a collection of over fifty vintage cars, from a Benz Patent-Motorwagen of 1897 to a Rolls-Royce Silver Ghost. The collection reflects the Alpine tradition of road travel that began with the Romans and has never ceased.
Conclusion
Martigny is a town that has been defined by movement. For three thousand years, people have passed through this crossroads on their way to and from the Great St. Bernard Pass, and each wave of travellers has left its mark. The Celtic Veragri, the Roman legions, the medieval pilgrims, Napoleon's Grande Armee, and today's tourists have all walked these same paths, drawn by the same geography.
The Roman remains in Martigny are not the most spectacular in the Empire, but they are among the most evocative. Here, you can stand in an amphitheatre where provincial Romans cheered and gasped, walk streets that followed the same lines as Roman roads, and hold in your imagination the image of a small but prosperous town at the foot of one of the great mountain passes of the world.
Practical Information
- Best Time: The amphitheatre and outdoor sites are best visited in spring or autumn. Summer can be very hot in the Rhone Valley. The Fondation Pierre Gianadda is open daily year-round.
- Wear: Comfortable walking shoes. The route is mostly flat and on paved surfaces.
- Bring: Water, sunscreen in summer, and a hat. The amphitheatre is fully exposed.
- Nearby Food: Martigny has excellent restaurants featuring Valais cuisine. Try the local raclette or a plate of assiette valaisanne (dried meat, cheese, and pickles). The Fondation Pierre Gianadda has a pleasant cafe.
- Combination: This tour combines well with a day trip to the Great St. Bernard Pass (open June-October by road). The hospice and its famous St. Bernard dogs are 35 km south.