The late Nordic Iron Age and Viking Age royal burial site of Borre in Norway: ALS- and GPR-based landscape reconstruction and harbour location at an uplifting coastal area

The Nordic Iron Age and Viking Age royal burial site of Borre on the western coast of the Oslofjord in Norway is an exceptional archaeological site in Northern Europe. The burial mounds, associated archaeological structures as well as geomorphological features have been analysed by a 1 × 1 m digital terrain model derived from airborne laser scanning. The interpretation of this data used different derivates of the digital elevation model including hillshade, slope map, local relief model and their combination. Additionally, ground penetrating radar profiles have been measured to investigate the internal structure of selected micro-topographic features. Based on the high-resolution topographic data, four smaller burial mounds were added to those previously known. Scandinavia is strongly affected by ongoing post-glacial isostatic recovery and, consequently, a sequence of elevated beach ridges were documented within the burial site down to the present shoreline. Local sea-level reconstructions in the Oslofjord indicate that the burial site of Borre was located close to the shoreline in the period of its use when the local sea-level was 3.5–5 m higher than today. Two prominent ridges between 4.5 and 0 m above present day sea-level are interpreted as Viking Age jetties facilitating safe landing on an otherwise unprotected coast.