The chapter Dialog in Art - Hidden Forms is based on a reflection of artwork (own installation with the title "193 m.a.s.l.") by pedagogical projects realized with students of gymnasium. On the main themes "Man and Place - secret dialogue"; "Artwork and Place - silent dialogue"; "Dialogue between Art and Public"; "Phenomenon of Postcard - imaginary dialogue (pedagogical project)" and "Desire for Dialogue" are presented examples of different approaches.