"The Place Where Lost Things Go" is a song from the 2018 film Mary Poppins Returns which was written by Marc Shaiman and Scott Wittman.
[1] It is a lullaby in which Mary Poppins (Blunt) tells to the children Annabel (Davies), John (Saleh), and Georgie Banks (Dawson), whose mother died before the events of the film, about "the place where lost things go", and that their mother is there watching over them.
[2] Shaiman and Wittman were inspired for the song's central idea by P. L. Travers' novels that inspired both the film and its predecessor, in which Mary Poppins takes Jane and Michael Banks (who in the film are Annabel, John, and Georgie's father and aunt, respectively) to the Moon, where they meet the Man in the Moon, who tells them that, in the dark side of the Moon, are the things that get lost.
[3] "The Place Where Lost Things Go" was released, along with the rest of the film's soundtrack, on December 7, 2018.
[4] On November 26, 2018, a clip from the film featuring Blunt's version of the song was released on Disney's YouTube channel.