Ancient structures are rarely preserved in a state where they are easily recognisable.  Most structures in Prehistoric, Roman and Medieval Britain were made of organic materials such as wood and have rotted away completely, leaving only the holes in the ground where the upright timbers were positioned (post-holes), or where horizontal timbers supported walls (beam slots).  In some cases stone foundations still exist, but they may be extremely fragmentary and damaged and altered by later activity such as stone robbing.  It is more common to find a fragment of a structure than a complete one; and these are often difficult to make sense of.  Even standing buildings such as castles and churches may have been altered, damaged and restored to the point where what we see today is very different to how they were when they were built.

 

In order to achieve an archaeological interpretation, what remains of the structures must be carefully recorded.  The recorded data is used to reconstruct a plan or three-dimensional drawing of what the structure is most likely to have looked like when it was created - or recreated from a previous version.  Post-holes are usually joined in a dot-to-dot style exercise to produce a plan of a building – it is easiest when the post-holes form a recognisable plan, are all similar in size and depth, and represent an obvious edge to the structure such as by surrounding a floor deposit.  Very often this is not the case and we are presented with a myriad of post-holes, stake-holes, small pits, ditches and fragmentary walls – all affected by later disturbance. With careful structural and dating analysis, the archaeologist may be able to make sense of this tangle of evidence – but the less clear-cut the evidence is, the more conflicting interpretations are usually possible.