A free internet resource called "Sub-Surf Rocks"! was launched in 2010. Its aim is to use seismic data obtained by the oil industry for enhancing the teaching of structural and economic geology at A-level (ages 16-18) in the UK. Seismic data gives a unique insight into the sub-surface and the many high-quality images coupled with ready-made (but adaptable) exercises can be downloaded to provide opportunities to improve students' understanding of structural features and their 3D visualisation skills. (Contains 2 figures and 5 online resources.)