The "Museum of Childhood" is a project connected to the Post-Graduate Program in Education at Unesc (Brazil) and since 2005 has been developing interfaces with research, teaching and extension. In this paper, the authors would like to show how the museological conception of the Museum of Childhood makes imagination from one of the central axis of its formative relation with the public. Such conception breaks with the traditional view of museums as buildings where old things are collected and preserved. In fact, the Museum of Childhood, in the light of its objective conditions, wants to be a museum without walls, a museum that, using the device of spatial demarcation, spreads itself in the university campus and other public places, with the objective of communicating with the people. This conception comes closer to the transgressive nature of modern arts, which desacralizes the work of art as masterpiece and proposed, for example, the fugacity of installations and aesthetic interventions. This conception takes the Benjaminian notion of the past as the dimension where other futures remain latent, that is, the museum is seen not as a guardian of the past, but as an establishment that wants to use its collections to communicate with the public. The overrunning of the static physical space, for example, forces the public to recreate its horizon of expectations concerning what a museum show be. In order to accomplish its original objectives, the Museum of Childhood works intensively on the formation of the public by proposing monitored visits in which creative activities are developed and by improving its homepage. (Contains 3 footnotes.)