Sideling Hill, Washington County, Maryland
(2016)

This is a geologic feature called a syncline exposed in a cut in a hill made to allow for a highway. The hill, itself may be a high point on the topographical map, but the dip in the middle is a relative low point in terms of geologic mapping of the rock units.

This was likely caused by the formation of the Appalachian Mountains in eastern North America during the past collision of what is now the continents of Africa and North America, causing bending and folding of existing rock layers into the shapes you see here.

Samsung S7 Edge Camera, stitched together by Google Photos' toolset.