In the present text it is presented the results of the research "Repositorio de altares espontáneos de memoria creados en Medellín, entre 1980 y 2014, en respuesta a la violencia asociada al conflicto armado". Objects or artifacts such as graffiti, crosses, virgins, plaques, gardens, etc., created to preserve the memory of violent events, are understood as spontaneous shires. It is considered that these altars can generate emotional responses, because certain agency possess them. These altars prepare the ground for the memory strategies of those who face the trauma of death, and are the vehicle for the commemoration. The creation of these artifacts propitiates the scenario for the realization of public mourning rituals, in which people express feelings, but it is also a form of political action to demand recognition of the damage caused, and a way of evidencing disputes or negotiations by the senses and meanings of the past. In the research, a virtual repository that allows to map and document the materialities with which the memory of the survivors and the victims of the armed conflict in the city is expressed was created. The repository allows showing trends in the construction of artifacts, identifying their creators, motivations for their construction, uses, meanings, and resignifications of those places of memory. It is understood that these materialities are spontaneous ways of recording violent events and processes of memory and resistance. These processes led to resume the discussion about the document and the activity it reflects; about the concrete and the ephemeral; about the file and the repository.