Solothurn makes a compact first impression: the Aare runs below a tightly drawn old town, and the Jura rises just beyond it. The Swiss canton capital is small enough to explore on foot, yet its streets carry several layers of history: a Roman settlement at a river crossing, a medieval political centre, a residence for French ambassadors and a modern regional hub for public services, commerce and culture. The river is not scenery added to a Baroque town; it is the reason a settlement grew here.
Population figures depend on the official series. The City of Solothurn’s resident-register summary reports 16,893 people for the municipality on 31 December 2025. The canton’s population publication gives 16,881 for Solothurn municipality on the same date. Both sources identify the municipal scope and date, but differ by 12; use one series consistently when comparing years rather than treating either figure as the population of the wider region.
Archaeology gives the Roman story firmer ground than a neat foundation legend. A Roman settlement called vicus Salodurum occupied the area around the first century CE. A drainage ditch uncovered in Löwengasse in 2024 belongs to a system laid out around 20 CE, and excavated remains show how the settlement stood close to an earlier Aare shoreline. In June 2026, divers documenting the railway bridge found timber piles from a fourth-century bridge: evidence for a river crossing long suspected by researchers. These finds make Solothurn a place to read as a working crossing and small Roman town, not as a city whose exact birthday is known. The local tourism history says the settlement was later turned into a Roman fort around 330. Christian tradition around Ursus and Victor is part of the town’s identity; it should be read as a religious tradition, not proof of every detail in their later legends.
The political story becomes unusually vivid in the medieval period. In 1038, Emperor Conrad II had his son Henry III crowned king of Burgundy at Solothurn. After the Zähringen line ended in 1218, the town gained the status of a free imperial city, then gradually assembled territory that became the canton. Solothurn joined the Swiss Confederation in 1481. From the 1530s, its alliance with France and the residence of the French king’s ambassador brought money and influence to local families involved in the French military service system. Their houses and civic buildings left the city with a Baroque profile that still frames daily life. The railway arrived in 1857; industry followed, and later the city shifted toward services and culture.
That history is visible in the ordinary route through the centre. Hauptgasse and the adjoining lanes hold arcades, fountains, shops, cafés and restaurants, while the Aare quay gives a quieter walk across the river-facing side of town. Solothurn’s famous number eleven is a civic motif rather than a mystery: the tourism guide traces it through fountains, buildings and local traditions. Its clearest expression is St Ursus Cathedral. Built between 1762 and 1773 to designs by Gaetano Matteo Pisoni and completed under his nephew, it has three flights of eleven steps, eleven altars, eleven bells and a tower 66 metres high. The cathedral treasury includes medieval, Gothic and Baroque goldsmith work. Check service times and seasonal access before entering or climbing the tower.
Allow time for at least one museum. The Museum Altes Zeughaus occupies a historic arsenal and displays more than 300 suits of armour from the fifteenth to seventeenth centuries, alongside weapons and changing exhibitions. Its handling stations make the collection accessible to families; labels are in German and French, with English information on a tablet. The Naturmuseum focuses on the region’s animals, plants, rocks and fossils. Its local highlights include fossilised turtles around 150 million years old from the city’s quarries and dinosaur tracks found at nearby Lommiswil; the museum says its permanent displays are wheelchair accessible and admission is free. The official museum directory also lists the Kunstmuseum, Museum Blumenstein, Schloss Waldegg and smaller specialist collections. Opening days vary, so check each museum’s current calendar.
For a half-day outdoors, walk from the centre toward the Verena Gorge. The approach to the gorge takes roughly 20–30 minutes; the signed route to the chapel is about two kilometres, 50 minutes and 40 metres of ascent. It follows a wooded stream to the hermitage, the hermit’s house and the Magdalene and Mount of Olives grottoes. The St Martin chapel is not open for general entry, although visitors can look through a small window during posted daytime hours. The route is described as suitable for strollers, but wet weather can still make a forest path slippery. Solothurn Tourism can arrange guided or torch-lit walks and provides maps at its office on Hauptgasse 69.
The Jura excursion begins at Oberdorf, reached by the S21 from Solothurn. The Solothurn–Moutier rail line reopened on 6 June 2026 after the Weissenstein tunnel works. From Oberdorf, the Weissenstein cable car reaches the ridge in about ten minutes. At 1,280 metres, the mountain offers marked walks, winter routes, restaurants and broad views over the Mittelland toward the Alps when conditions are clear. Check the railway, cable-car operation and mountain weather before setting out; a panorama is not guaranteed by the timetable.
Another route follows the Aare west. From May to October, the seasonal boat from Solothurn to Biel/Bienne takes just under three hours and passes the stork colony at Altreu, the historic town of Büren an der Aare and the lock at Port. It makes a useful contrast to the cathedral-and-museum day and gives a sense of the river’s role in connecting the region. The operator asks passengers to recheck its online timetable shortly before travel. Nearby Bern, Biel and Burgdorf also have direct rail connections, while SBB lists direct long-distance trains from Solothurn toward Zurich and Geneva. From Basel, plan a connection through Olten. Train patterns change with works and season; check the SBB planner for the day you travel.
Solothurn’s own business overview describes roughly 500 companies and about 20,000 jobs in the city, alongside its role as cantonal capital and a service and cultural centre. Those figures are an orientation from the municipal economic page, not a census of the wider district. Visitors will find accommodation listings, walking tours, practical maps and regional excursion advice through the tourist office; the city also has parking garages, a bus network and a pedestrian-oriented old town. A good first visit pairs the cathedral and old streets with one museum. A second day can be shaped around the gorge, the Weissenstein or the river boat, depending on weather and season. Check current opening hours, transport connections and excursion conditions before departure.