The John Lennon Wall is located in Mala Strana near the French Embassy in Prague. Since John Lennon’s murder by Mark David Chapman in 1980, the wall has filled up with John Lennon-inspired graffiti and song lyrics.
The wall is continuously changing. The original portrait of Lennon and subversive anti-communist messages are long lost under several layers of paint. The wall is owned by the Knights of the Maltese Cross, who allow the graffiti to continue.
Getting there: From Malostranska metro station take trams number 12, 20, 22, or 23. The wall is a short walk from either Malostranske namesti or Hellichova stops.
Sources: John Lennon in Prague [Prague.net] and Lennon Wall [Wikipedia].