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).
the ongoing downfall of Checo is really astounding. Maybe I'm just losing perspective on his performance because his teammate is checks notes on track to be one of the true GOATs, but it really seems like he's been beefing it.