Koblenz, Germany. Curated by The Heike Strellow Gallery in Frankfurt and commissioned by the Koblenz Garden Festival, it is hoped this work will remain permanently. It is sited in the grounds of the Fortress which overlook the confluence of the Rhine and the Mosel. The cliff itself is made of slate which underlies most of the region, giving the wines a distinctive taste. The material used was refuse from s slate making factory. 14 m. in diameter.