Erratic boulders…
Around 200 rocks – some of them very large – were unearthed during the excavation work for the Zentrum Paul Klee after being buried in the soil at Schöngrün for more than 10,000 years. Technically these rocks are known as erratic boulders and were originally swept along by the Aare Glacier during a late phase of the last Ice Age (the Würm glacial stage). The outlet glacier from the Bernse Oberland consisted of many individual glaciers and carried lots of medial moraines along its surface (rock flows).

Adjoining ice flows, unlike flowing water, do not mix, which means that medial moraines are preserved over the entire length of a glacier tongue. During the Bern phase of the Aare Glacier the medial moraines had sufficient time to build large moraine stacks, which today surround Bern in a wide arc. The land that the Zentrum Paul Klee stands on is located on the end fill of one of the two largest medial moraine strands.

… with new function
Many of the boulders that began their thousand-year journey to Schöngrün on the back of a glacier in the Bernse Oberland some 15,000 years ago today adorn the two ponds on the southern periphery of the Zentrum, which the Müller family also donated to the Zentrum Paul Klee and the district.