Seahenge is a bronze-age wooden formation discovered in 1999 just off the coast of Norfolk, England at Holme-next-the-sea. It comprises a number of small oak trunks forming a vertical fence arranged in a circle. One of the trunks has a Y fork permitting access to the central area. In the centre of the ring is a large inverted oak stump.
The, presumably religious, site was discovered because unusual weather conditions resulted in a lowering of the sea level of the coast for a short period. Since the entire structure had been in an anaerobic waterlogged state for several thousand years, the logs had survived with little damage.
Exposure to the air put them at immediate risk and English Heritage arranged for the wood to be transported to Flag Fen near Peterborough, England where the wood is being continually soaked in a wax impregnated water to slowly (over the years) replace the cellulose in the wood with wax. When this is complete it is hoped to recreate Seahenge.
It is possible to date the creation of Seahenge very accurately since the rings on the trees can be correlated with other overlapping tree ring variations etc and the date of felling the oaks is known to better than one season (2049 BC).
It is so named in obvious comparison with Stonehenge.