There is still evidence in Basel of the large earthquake that shook the city about 650 years ago - that is, if you know where to look.
Archaeologist Karin Meier-Riva points to where the straight line dividing the cathedral's outer wall from the tiled roof becomes crooked. Not far below, a series of metal girders holds the bricks together.
They are small signs of how Basel's cathedral bent but did not break during the earthquake of 1356, which was the strongest ever to hit western Europe.
The roof above the nave collapsed, a couple of towers crumbled and fell into the River Rhine below, and at least one person was killed by a falling stone while he prayed.
Spiritual life insurance
Within years of the quake, the cathedral had been rebuilt. "The people of Basel invested in its reconstruction to protect against other disasters and earthquakes," says Meier-Riva. "It was like a life insurance."
During the restorations, the east-facing towers were not rebuilt, but the empty tower bases above the choir bear witness to their medieval fate. As does a circular stained glass "wheel of fortune" window, which lost its shape under the weight of the trembling walls.
Meier-Riva has brought the story of the 1356 earthquake to life with her contributions to an exhibition, called "The earth trembles, here as well", at Basel's Natural History Museum.
In a special section of the exhibition, she has reconstructed the events of that autumn day in 1356 through the eyes of medieval objects that withstood the tremors.
The Atlas figure, one of the many sculptures lining the cathedral walls, recalls the wailing population, as well as the last discordant sounds from the pipes of the church organ before it was smashed to bits.
The display also includes a bronze wine measure, cast shortly after the earthquake, which was used to ration out the scarce supplies of wine, since most stocks had been buried under the rubble.
The medieval European, according to Meier-Riva, did not have a Richter scale. Tremors were measured and remembered according to the points of reference important for a 14th century resident of Basel.
"The earthquake endured as long as it takes to say a Hail Mary, for example," explains Meier-Riva. "The earthquake started when the bells were ringing to call people to Vespers. We know it happened in autumn because the wine harvest was underway."
Special tours of Basel and the surrounding area are also being provided to show the earthquake damage. Besides the cathedral, guides make a stop at the Lohnhof tower at a corner of the city's former walls.
Until a few years ago, it was thought that the tower was built after the earthquake. However, recent excavations have proven otherwise. Archaeologist Christoph Matt discovered a clear diagonal line running like a fault through the masonry.
Stones to bricks
The stones on one side of the line date back to the 11th century and survived the tremors. The masonry work on the other side reveals finer workmanship to that found during the 11th century, and includes bricks, which were first used in Basel 200 years later.
The Teufelhof restaurant and hotel is the next stop on the tour. The Teufelhof sits on top of a pit that once ran round the outside of the city walls and served as the rubbish tip.
The basement of the restaurant has been excavated to reveal old stone walls and layers of soil, gravel and pottery fragments that are yet more evidence of the 1356 earthquake.
"There was no find of ceramics in this layer that dated later than 1356, so we know that this layer must have been filled in suddenly after the earthquake," says Meier-Riva.
Dozens of castles were destroyed or damaged in the earthquake. The road leading to the ruins of Löwenburg castle, about 45 minutes outside Basel, follows the fault line.
The castle, which was never restored to its former splendour, stands alone at the edge of a forest in the Jura countryside. The fallen stones were carted away in the early 16th century and used in the building of a nearby priory, which still flourishes today and houses a small museum dedicated to the Middle Ages.
Even though the earthquake of 1356 was the strongest ever to hit western Europe, it was only the last in a string of disasters that befell the people of the region in the 14th century - and it was far from the worst.
More than a third of Basel's estimated 12,000 residents were killed in the plague that swept through the city a few years earlier compared to the few hundred who died in the earthquake.
Worryingly for inhabitants of modern-day Basel, scientists are not ruling out another major earthquake, but no one knows when it will strike.
by Dale Bechtel
Doing the tour:
The exhibition, "The earth trembles, here as well", runs until mid-November. It puts the emphasis on interactive and visual displays, but the captions are in German only. A number of special events accompany the exhibition, including walking tours of the city. Some of these will be in English. Contact the Natural History Museum.