The identification of activity areas in archaeological sites is an important part of archaeological research contributing to the reconstruction of past ways of life. The threshing floor is an activity area that relates to subsistence practices in agricultural societies, yet identifying threshing floors in the archaeological record is difficult. We present a geoarchaeological study conducted at an Iron Age layered feature unearthed in 1998 at Tel Megiddo, Israel, in which we tested a previous assumption that it represents the remains of a threshing floor. Using micromorphology, mineralogy, elemental analysis, phytoliths, and dung spherulites, we show that the materials comprising the bulk of the layers in the Megiddo feature include large amounts of wood ash and the inorganic remains of livestock dung. Based on these results, coupled with ethnographic data on threshing floors and observations on the macroscopic traits of the feature under consideration, we conclude that the layered feature at Megiddo does not represent a threshing floor but a single-household trash heap. We suggest that the interpretation of similar features at other archaeological sites as threshing floors be reevaluated.