This project aims to reconstruct the development of the Holocene northern barrier spit of Sylt, an island located off the southern German North Sea coast. The sedimentary architecture of this spit system was investigated through an integrated approach, using ground-penetrating radar (GPR) and sediment core data. The presented method provides an excellent tool for efficient, high-resolution spatial analysis of sedimentary facies and stratigraphy of sandy coastal areas in temperate climates. The models developed for the spit’s sedimentary dynamics provide a framework which may also be applied for interpretation of other sedimentary successions which formed in similar settings. A new stratigraphic model for the northern barrier spit of Sylt is presented, showing that the spit’s latest Holocene development is much more complex than previously thought.