Subrosion is the subsurface leaching of soluble rocks. It is a global phenomenon and a geohazard in urban areas because it causes depressions and sinkholes. This is the case in the study area, the town of Bad Frankenhausen, in northern Thuringia, Germany. Using shear-wave seismic reflection we are able to image these structures at high resolution to a depth of ca. 100 m. We observe that the underground is strongly fractured and there are indications of cavities.