On June 2012, the last of the coal mines operating in the Saarland region in west Germany closed, marking the end of a 250-year history of mining in the region. Four years later, a 30-meter-tall structure called ‘The Polygon’ was erected on Bergehalde Ensdorf, one of the biggest slag heaps on Saarland, that rises some 150 meters above the surrounding Saar Valley. Due to its exposed location, the polygon is visible from all around the valley. Those who ascend to the top of the structure, to the 35-meter long platform, are treated with a magnificent view of the land around and the city of Saarlouis.

Designed by Berlin architect Katja Pfeiffer and Oliver Sachse, the walk-in monument consist of two slanting towers connected by a bridge. Depending on which direction you look at the monument from, ‘The Polygon’ changes shape, assuming the form of a rectangular arch, an inverted triangle, an inverted V, an hourglass-like structure and finally like the alphabet T falling on to its side. The shape of ‘The Polygon’ itself vaguely resembles the supporting structures that have been used in underground mining.

Photo credit: www.sr.de