As Nature Neuroscience celebrates its 25th anniversary, we are having conversations with both established leaders in the field and those earlier in their careers to discuss how the field has evolved and where it is heading. This month we are talking to Fernando de Castro Soubriet, principal investigator at the Instituto Cajal (Spain). He is a neurodevelopmental biologist who is actively involved in championing the history of neuroscience. He is among the group of Spanish scientists who ensured that the Archives of Santiago Ramón y Cajal and the Spanish Neurohistological School are registered as World Heritage with UNESCO (United Nations Educational, Scientific and Cultural Organization). Here, we discuss science and the legacy of the Spanish Neurohistological School.