Picture taken on July 27, 2019 shows a view of the Tetraeder , a steel structure in the shape of a tetrahedron located on top of the Halde Haniel...
People visit the Tetraeder , a steel structure in the shape of a tetrahedron located on top of the Halde Haniel mine dump, on July 27, 2019 in...
March 2019, Baden-Wuerttemberg, Heidelberg: Ernst Fritz-Schubert, Systemic Therapist at the Fritz Schubert Institute, holds a tetrahedron with the...
Man walks down the tetrahedron at the dump Beckstrasse in the setting sun in Bottrop, Germany, 10 December 2013. Photo: Marius Becker/dpa | usage...
