Cobblestone mosaics (Freiburg im Breisgau)

Even though the bombing of Freiburg on 27 November 1944 destroyed about 38km of roads and pavements, many of the pavings survived and can still be admired today.

For instance, the pavements of Kaiser-Joseph-Straße, Freiburg's main shopping street, was paved with red porphyry and decorated with bands of white marble and smaller cobbles found in the Rhine.

The round mosaics, decorative bands and at times even the paving of whole alleys consist mostly of coloured cobblestones from the Rhine.

In the past, the stones used to be extracted from the Rhine flood plains close to Breisach in periods of low flow.

Other stones like porphyry, granite, basalt and marble have been purchased in Europe in the past and are obtained from all over the world today for economic reasons.

To attain flat ellipsoidal cobbles, the paving stones are either cut by machine and have their edges smoothed in a drum mixer, or they are manually broken down and trimmed underneath to improve their stability.

Some of these mosaics have mere ornamental character, others display emblems, coat of arms or short brand names.

If these round mosaics take great effort to piece together they are assembled with the help of a wooden stencil in a steel ladle filled with mortar.