The earliest peat in this region was layed down about 7000 years ago and may be part of the land bridge that existed between Britain and the rest of Europe. Much of what is now the North sea is thought to have been low-lying fenland.
Roughly 6000 years ago the area was inundated by the sea for the first time, a little over 5000 years ago peat once again began to form as a result of a brief fall in sea level. The bogs were colonised by alder, elm, oak and hazel. The first evidence of human activity is of mesolithic hunter gatherers. There have been frequent finds of the bones and antlers of red deer, some of these antlers have been worked for use as tools.
Around 3000BC pollen records show that the trees were in decline and grasslands were on the increase. At the same time charcoal appears in the deposits. Finds including flints, axes and cut timbers have been found in the deposits.
In 1971 the skeleton of a neolithic man was discovered. The man aged between 25 and 35 had been placed in the peat in a crouched position on his right side. near his right elbow a small group of flints had been placed and there is evidence that his body had been covered with birch twigs.
The peat beds exposed at low tide in Hartlepool Bay are among the largest areas of ancient mesolithic landscape still to be seen.