Due to its favourable setting, the area around Seis was settled very early on in history, as far back as 2000 BC. The Wallburg fortresses on the Laranz ridge to the north of Seis date back to this time. The inhabitants of these fortresses were Rhaetians or, more specifically, natives of Isarck. A bronze sword found on Hauenstein provides evidence of a further hill settlement in that area. In the Iron Age, settlements were established on Gschlier and Runggereck. In Gschlier (in the Laranz Forest), archaeologists have discovered many pieces of Southern Alpine querns typical of those used in the Middle Iron Age. A further impressive Wallburg fortress can be found in Runggereck, in the area around Laranz. It is, however, impossible to date and classify the finds from this area with absolute precision. Iron Age ceramics have been discovered and, underneath them, numerous pieces of pitchers and bowls. The remains of these Wallburg fortresses in the Laranz Forest can still be seen to this day.