Medieval castles spring to mind when you see them. Many people are even reminded of Castel del Monte, the famous southern Italian palace of the Hohenstaufen Emperor Friedrich II. All of a sudden, 24 slim, brickwork towers appear on the Lusatian horizon. Round and windowless, they rise 22 metres into the sky above the industrial town of Lauchhammer. In groups of four they cluster around common stairwells, resembling the leaves of a clover. Inside they are full of loose slag bricks once coated with a film of bacterial sludge. They are actually called tower-type trickling filters, because the would-be castle is really a decommissioned trickling installation for the biological purification of coking plant wastewater containing harmful substances. Today, one of the towers can be climbed and offers an impressive view over the area of the former large coking plant from the glazed observation towers.
The Lauchhammer bio-towers are the last-remaining remnants of what used to be a powerful established industry. In 1952 the world’s first large-scale coking plant came into service right on the doorstep, manufacturing high-temperature coke from lignite. As imports of bituminous coke from the Ruhr region began to run dry, this technological breakthrough enabled the former GDR to replace it with its own supplies. Lauchhammer laid the foundations for the expansion of the East German metallurgy industry. Briquetting plants and power stations started springing up in the industrial haze surrounding the town. Not a single brick remains. The demolition fever of the post-1989 era did more than flatten factories: it damaged the identity of Lauchhammer and its people. This gives the bio-towers even greater significance. Their shape and size is unique in Germany but, above all, they ensure that memories of the industrial past do not trickle away without trace.