The Cell Block where Nelson Mandela was imprisoned, Robben Island, Western Cape Province, South Africa, Africa

Cell block of the women's concentration camp Ravensbrueck, Brandenburg, Germany, Europe

Cell block of the women's concentration camp Ravensbrueck, Brandenburg, Germany, Europe

Rack for beatings in a cell of the cell block of the women's concentration camp Ravensbrueck, Brandenburg, Germany, Europe

Aerial picture, roof with solar panels, rotunda, Alt-Oer retirement home, Oer-Erkenschwick, Ruhr Area, North Rhine-Westphalia, Germany, Europe

View into a cell block in the prison, Alcatraz Island, California, USA

View into a cell block in the prison, Alcatraz Island, California, USA

View into a cell block in the prison, Alcatraz Island, California, USA

View into a cell block in the prison, Alcatraz Island, California, USA

View into a cell block in the prison, Alcatraz Island, California, USA

Aerial picture, roof with solar panels, rotunda, Alt-Oer retirement home, Oer-Erkenschwick, Ruhr Area, North Rhine-Westphalia, Germany, Europe

Cell Block D in prison, for special prisoners such as Al Capone, Alcatraz Island, California, USA

Solar Village with solar roofs, Freiburg, Baden-Wuerttemberg, Germany, Europe

Solar Village with solar roofs, Freiburg, Baden-Wuerttemberg, Germany, Europe

View into a cell block in the prison, Alcatraz Island, California, USA

View into a cell block in the prison, Alcatraz Island, California, USA

Exterior, cell block, Alcatraz Island, California, USA