Ключевые слова: activity, area, bicycle, city, converted, cycling, cyclist, europe, european, former, gelsenkirchen, german, germany, halde rheinelbe, heap, industrial, industry, north rhinewestphalia, park, place, public, recreation, recreational, recultivated, recultivation, renatured, repurposed, ruhr, ruhrgebiet, slag, slag heap, slagheap, stockpile, town,