BASEL, AD 20–1815

Archaeology at
St. Alban-Graben

From 2018 to 2021, construction of the Kunstmuseum carpark was monitored by the Archaeological Service of Canton Basel Stadt. The finds from the archaeological investigations provided a fascinating insight into the history of Basel.

The excavations at St. Alban-Graben brought to light the remains of two Roman well shafts. Probably in combination with cisterns, wells such as these guaranteed a steady supply of water for the Roman-period settlement. The bottoms of both newly discovered wells were found 13 m (almost 43 feet) below the present-day surface. Photo: ABBS, Martin Allemann.
As well as partial skeletons of horses and dogs, remains of at least three adults and two infants were found in one of the Roman wells. Although human skeletal remains have also come to light at other Roman sites, we have not been able to solve the mystery of whether these were special burials or whether the dead were just “discarded”. Photo: ABBS, Martin Allemann.
A lancehead, whose tip had been broken off in Antiquity, came to light in the same well shaft that contained the animal bones and human remains. The two wells were infilled some time in the Roman period, when they fell into disuse. Photo: ABBS, Philippe Saurbeck.
From the 1st century AD onwards, a settlement grew up in the area of what is now Freie Strasse, Rittergasse and Dufourstrasse. At the time it was situated on the Roman arterial road, which ran alongside the River Rhine all the way to the North Sea. Fragments of ceramic vessels such as this bowl from the South of France attest to the far-flung trade networks that existed in Roman times. Photo: ABBS, Philippe Saurbeck.
In Late Antiquity, a fortification wall was built around Basel’s Münsterhügel hill. The site was used as a garrison for military units and as a refuge for the civilian population. An archaeological investigation of the area outside of the fortifications brought to light 101 Late Roman coins. Photo: ABBS, Philippe Saurbeck.
The coins retrieved during the excavation suggest that a suburb (in Latin suburbium) existed outside of the Late Roman fortifications. Its buildings were probably made of timber; because wood decays in the ground, no remains of houses have survived the passage of time. Photo: ABBS, Fabian Bubendorf.
Antoninianus of Tetricus (AD 271-274). Photo: ABBS, Philippe Saurbeck.

This is where we excavated

St. Alban-Graben
CH-4051 Basel

The name of the street, “St. Alban-Graben” ( in English St. Alban’s Ditch ), reminds us that this was where the defensive ditch of the early 13th century inner city wall was once located. Construction of a new carpark at the Kunstmuseum required deep intrusions into the ground, both at the site of the former city moat and in an area directly adjacent to it, which had been developed since the Roman period.

Although a massive trench was cut into the Roman-period features when the inner city wall and its moat were built in the Middle Ages, archaeologists were able to record the final remnants of the Roman settlement, which had existed from the 1st century onwards in front of where the Kunstmuseum stands today. What came as quite a surprise was the discovery of two dry-wall Roman shafts beneath the medieval city moat at a depth of 7 m (23 feet). Originally used as wells, the shafts were later filled with partial skeletons of horses and dogs and even human remains.

Remnants of the medieval city wall, or so-called inner city wall, were uncovered in various locations during the construction project beneath the footpath and the façades of the present-day houses on the side of the street facing Münsterhügel hill. The skeleton of a Barbary macaque, which came to light in a latrine tower built onto the city wall, was a sensational find. The animal had been kept as a pet in the Middle Ages. Healed bone fractures and traces of inflammation suggest that it was rather ill-treated.

Several fragments of tombstones found during the excavation came from the cemetery of Basel’s first Jewish community, which was located at Petersplatz square. The persecution of Jews following an outbreak of bubonic plague in 1348/49 led to the community being crushed and driven out of the city; the cemetery was destroyed, and the tombstones reused as covering slabs for the countermure (the retaining wall of the city moat). When the moat was abandoned, the tombstones were removed and reused a second time to build drainage shafts at St. Alban-Graben in 1815. This was where they were discovered by the archaeologists.

Find out more about the results of the excavation (in German only).

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Find out more about excavations of the Archaeological Service of Basel Stadt (in German only).

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The free audio guide app by the Archaeological Service of Basel Stadt shows you around four original sites from the Celtic, Roman and medieval periods of Basel’s history, where archaeological information points have been set up.

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The inner city wall was a visible part of the cityscape until quite late in the 19th century and still survives indirectly in some of the street names and in a number of streets that follow its original course. The St. Alban-Graben, the Leonhardsgraben and the Petersgraben all recall the city moats that were once located there, with “Graben” being the German word for “ditch”. The inner city wall was 10 to 13 m (33 to 43 feet) high. Its last remnants were uncovered in various locations during the construction project beneath the footpath and the façades of the present-day houses on the side of the street that faces Münsterhügel hill. Photo: ABBS, Philippe Saurbeck.
Like many other medieval cities, Basel grew in concentric circles around an old core and had several medieval fortifications, the oldest two of which were located at today’s St. Alban-Graben. Most of the surviving features, however, belonged to the inner city wall, which was built between 1200 and 1250. Photo: ABBS, Martin Allemann.
As well as gates, the inner city wall also had several towers, some of which were added at a later date. One of these was a square tower used as a latrine. Its remains were discovered outside the Credit Suisse building. Photo: ABBS, Philippe Saurbeck.
The St. Alban’s diaphragm arch (St. Alban-Schwibbogen) was a gateway tower in the inner city wall located at the entrance to Rittergasse lane. View of St. Alban’s diaphragm arch with the “German House” as seen from St. Alban-Vorstadt. Watercolour by J. J. Schneider (probably after J. J. Neustück), 1800–1850. Painting: StABS Bild Schn. 54.
From 1784, the St. Alban-Graben was infilled and, over the course of the 19th and 20th centuries, what was left of the city wall was either demolished or incorporated into new buildings. The gates or arches were demolished, the Aeschenschwibbogen in 1841 and the St. Alban-Schwibbogen in 1878. View of Rittergasse lane from St. Alban-Vorstadt after the arch had been demolished. Photo: StABS Bild 2, 115.
One of the highlights of the excavations was the discovery of a monkey skeleton in a medieval latrine tower built onto the inner city wall. Evidence of monkeys from before 1500 are rarely found and usually consist of a few isolated bones. The latrine tower in Basel was so narrow that it had to be excavated manually, one bucket at a time. Photo: ABBS, Philippe Saurbeck.
Pet monkeys could wreak havoc when left unsupervised. Images such as this one on a tapestry from Cluny show monkeys on leashes or chains that have a large weight attached to the other end to restrict their movement. Deposits and discolorations on the skeleton suggest that the Basel monkey was also tethered in some way. Photo: RMN-Grand Palais (musée de Cluny – musée national du Moyen Âge, Michel Urtado).
The monkey skeleton was almost completely preserved. Missing parts including some of the finger bones and a few ribs either decayed in the ground or were not recovered during the excavation. This means that a complete cadaver was disposed of in the latrine. The skeleton tells us a lot about the monkey and its condition. Its canine teeth, for instance, show that it was male and the surfaces of its joints indicate that it was between 6 and 8 years of age. Diseases and injuries, including a healed rib fracture and a healed comminuted fracture of the upper jaw bone can also be seen. Photo: ABBS, Philippe Saurbeck.
Latrines were used, not just as toilets, but also for the disposal of refuse. The latrine tower at St. Alban-Graben was no different; as well as the monkey skeleton, it also contained cooking vessels, broken glass, stove tiles and food waste. Thanks to a relatively soft landing, six pots, which were discarded either during alteration work at the property or when its owners moved away, even survived the 10-metre drop into the latrine tower intact. The pottery and the stove tiles that were found lying on top of the monkey bones allowed us to date the animal’s death to between 1350 and 1450. Photo: ABBS, Philippe Saurbeck.
The tombstones found at St. Alban-Graben came from the cemetery of Basel’s first Jewish community, which was located at Petersplatz square. Because the Jews were blamed for the outbreak of bubonic plague in 1348/49, the community was crushed and driven out of the city, the cemetery was destroyed, and the tombstones reused as covering slabs for the countermure (the retaining wall of the city moat). When the city moat became defunct in the 19th century, the tombstones were reused a second time to build drainage shafts. The tombstone shown here was the only one that still bore a legible name. Apparently it was the tombstone of Hannah, who lived in Basel more than 700 years ago. Photo: ABBS, Philippe Saurbeck.
The ten fragments of sandstone tombstones found during the recent excavations had been used as building blocks in two drainage shafts constructed at St. Alban-Graben between 1815 and 1820. To ensure stability, the builders needed to use high-quality stone blocks of uniform size – and the tombstones fitted the bill. Photo: ABBS, Martin Allemann.
The tombstone fragments were brought to the Archaeological Service’s stone depot, where they were cleaned and studied in an attempt to decipher their inscriptions. Since the late 19th century, some 50 Jewish tombstones from the Middle Ages have come to light during construction work or in archaeological excavations throughout Basel. Photo: ABBS, Martin Allemann.

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