It’s a “sunken lane” or “hollow way,” and it’s most likely caused by a few hundred years of very specific erosion (amusingly the lead image for the Wikipedia article for this phenomenon is the same as the post).
It’s a “sunken lane” or “hollow way,” and it’s most likely caused by a few hundred years of very specific erosion (amusingly the lead image for the Wikipedia article for this phenomenon is the same as the post).