These were probably small bodies of water in the distant past. Here, a peat bog has formed as a result of the water filling in.
Archaeological digs around the area have revealed traces of human habitation dating back to the Bronze Age (2200 BC), the Iron Age (800 BC) and Antiquity (52 BC). Thanks to the human-made bonfires and their subsequent radiocarbon dating, we have been able to go back in time.