While touring Chepstow Castle we came across this old door with an inscription beside it which read "Until 1962 these doors hung at the main castle gateway when they were copied and replaced by the present doors. Their age was recently tested by dendrochronology (tree-ring dating) and they were found to have been made not later than the 1190s. This surprisingly early date makes these the oldest castle doors in Europe, and it brought about a review of Chepstow Castle's history."
Amazing eh - a wooden door almost 1000 years old, wow.