Although it is rarely seen, the remnants of a past forested landscape, where there is now sea and beach, is a very interesting feature and teaches us about past sea level rise and our recent glacial history, and makes sense of some of the archaeological remains we find around our coastline in West Wales.

At the end of the last glaciation the sea level was much lower than it is today because so much water was still locked up in the ice sheets to the north of Britain.  As the climate warmed forests became established on land that had been tundra for thousands of years, and this forest extended far out beyond where sea level is today.  Gradually as temperatures rose, the sea ice to the south of the arctic circle melted and sea levels rose, submerging much of the coastal forests.

In some places this action was very rapid…