This volume brings together studies that combine both traditional and contemporary tools in the study of syntactic geolectal variation, with a special focus on a subset of Iberian varieties. There is an increasing body of research on syntactic micro-variation, but the interaction between dialectology (which makes use of atlases, corpora, databases, questionnaires, interviews, etc.) and formal syntactic studies has traditionally been weak (or even nonexistent), which is precisely the gap the contributions in this book aim at filling in. From a broader perspective, this collection is meant as a contribution to the subfield of linguistic variation and to the more general field of Romance linguistics, with special interest in Spanish and in other Iberian languages. The volume is meant for both researchers and students interested in linguistic variation or dialectology and, specifically, in syntactic variation in Iberian languages.