"There were 55 large oak posts within the circumference of the circle and one smaller upright timber. The timbers were set side by side in an elliptical circumference around an inverted oak tree.
Upon excavation timbers 35 and 37 were found to be the two forked branches of one trunk or branch."
Proceedings of the Prehistoric Society VOLUME 69, 2003
The Survey and Excavation of a Bronze Age Timber Circle at Holme-next-the-Sea, Norfolk, 1998–9 by Mark Brennand & Maisie Taylor
THE AUBREY HOLES REVISITED C.T.Daub Department of Astronomy, San Diego State University, San Diego, CA 92182-0540, USA 1993
Quarterly Journal of the Royal Astronomical Society, Vol.34:4/DEC, P. 563, 1993
The coincidence of there being 56 outer timbers at Seahenge was pointed out to me on my visit to see the fantastic exhibition of it at King's Lynn where I was generously shown round by Francis Pryor.