During the Second World War, Warsaw became a prison and a place of mass shootings. The city was almost destroyed. Only a small part survived. The atmosphere in the courtyards reminds of the scenery in the theatre, with its own plots and stories. A return to reality occurs when you see trees growing in the yards. They have adapted to the unusual environment and survive in spite of everything, just like people living in the Warsaw ghetto during the war years. These trees are the main characters of these places, living witnesses of that difficult time. This is a history textbook created by nature and time to remember everybody who lost their lives in the most terrible times.