The trench (right) is seen looking west at a section through the gravel layers to show the OGS or 'old ground surface' (the black layer).
This would have been the original land surface when building first began at the site in 1207.
When the octagonal keep was constructed the whole surface area was raised by nearly 1.5 metres with dumps of gravel and stone.
Some structures were built directly onto this horizon, and some pits (e.g. the water-filled hole in the foreground) where dug into it. When the octagonal keep was constructed the whole surface area was raised by nearly 1.5 metres with dumps of gravel and stone.
Buildings were constructed on top of this 'old ground surface' and cess-pits were dug into it.
The surviving fragments of these early buildings included the lowest course of a finely decorated doorway, which had been blocked-in during the lifetime of the structure it served
Looking west (left) of the blocked doorway of a high status building constructed on the 1207 ground surface.
This may be the 'domus regis' or king's house referred to in the documentary sources.