The Autumn 2011 (vol. 13 no. 3) issue of the Nexus Network Journal features nine papers guest edited by José Calvo-Lopez dedicated to the theme From Mediaeval Stonecutting to Projective Geometry . This is an outgrowth of the session by the same name which took place during the eighth international, interdisciplinary conference Nexus 2010: Relationships between Architecture and Mathematics, held in Porto, Portugal, in June 2010. The topics discussed range from the theoretical mathematics to built examples both historical and contemporary. The issue is completed with other research papers, conference reports and book reviews.