At the beginning of the Spanish Civil War the republican authorities started organising what came to be known as "children's colonies". These children's colonies became both home and school for all the children who were evacuated from Madrid. The purpose of this article is to study in depth the transformation of many of these children's colonies into educational communities. The teachers accompanying the children often shared the republican ideals of "active citizenship" and strove to make conscious citizens out of these children. The educational model chosen for achieving this aim was the community model, based on the transformation of every children's colony into a self-sufficient community of teachers and students, along the lines of similar experiences organised by the international New Education movement in the 1920s and '30s. The article discusses the iconic experiences of children's colonies during the Spanish Civil War and the ways in which their different concepts of "community" were represented. By studying the photographic collection put together from different public and private archives alongside the written information preserved in unpublished diaries we are able to develop a methodological model for analysing the construction and/or destruction of the community ideal in these educational experiences.