Statesman International holds a letter-writing marathon on December 8 and 9.
Portraits of political prisoners from different countries will be drawn on the wall on the corner of Górczewska Street and Al. Prymasa Tysiąclecia, Radio Racja reports.
A portrait of Belarusian human rights activist Ales Byalyatski will appear among others.
Letters written during the marathon will be displayed on the wall.