Stave churches were once common throughout northern and north-western Europe. Now, with a few exceptions, these medieval wood constructions are only found in Norway.
Surviving stave churches mostly date from 1150-1350 or so we thought. According to a new analysis, though, they may be a bit older than previously believed.
Normally, the age of wooden churches is measured from the analysis of individual logs. Cores are taken from logs and dated by tree rings, which are compared to already dated technology. This technique, which is called dendrochronology, is invasive, however, and not recommendable in some of the very old churches. It also has some limitations in terms of accuracy which is why researchers are now trying out a new approach.