Jerzy Bereś ( 1930 - 2012): Living Monument "ARENA", Wrocław, Poland, 1970
http://en.wikipedia.org/wiki/Jerzy_Bere%C5%9B
Two semicircles - one planted young trees, the second - a monument of destruction - the tree roots showing up.
On the middle the bench to contemplate the truth about man, the truth about the consequences of the development of our civilization.