“Pit alignments are a little-known type of prehistoric monument found throughout the British Isles, the function of which is at present poorly understood. They consist of a series of evenly spaced and often relatively shallow pits arranged in lines. These monuments are most frequently discovered through aerial photography, being morphologically well suited to identification by this method. Some alignments run for large distances, in straight or curving lines, and clearly represent massive undertakings by large numbers of people or by smaller numbers over long periods of time.”
Their original purpose is unknown - theories for their origin include, as agricultural boundaries, or for some kind of ritual use.