3D model of the stone-lined depression (IMAGE) Stockholm University Caption Digital 3D model of stone packing in one of the investigated trenches. On top of the stone packing was a layer of sand and originally there was also a wooden boat slip at the bottom. Traces of this can be seen in the form of post-holes and a stone frame at the bottom. View to the south. Photogrammetry, modelling and image produced by Fredrik Lundström. Credit Fredrik Lundström Usage Restrictions May be used in connection to the related research License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.