This is a collapse of tufo drain and its associated cover. There is a square depression carved into the surface (leaving a raised border measuring approximately 18cm), which may be associated with the depression on one of the adjacent tufo blocks to the west (2068). This cover enclosed what seems to be a basin, but the boundary between the end of the drain and the beginning of the open basin is unclear as of now. During post-excavation study, this feature was reinterpreted as a collapsed wellhead.