Cropmarks of a keyhole-shaped, ditched enclosure, to the south-east of Mawers Plantation, South Willingham. Identified on aerial photography examined as part of the National Mapping Programme. The NMP photo interpreters were of the opinion that the cropmarks represented the remains of two conjoined Bronze Age round barrows. {1} Further analysis of the aerial photographs suggested that these cropmarks more likely represent the remains of a Neolithic long barrow, given the continuous oval-shaped nature of the cropmarks. The feature's location on the high shoulder of a natural spur also conforms with other known long barrows in this area. The cropmarks are visible as an elongated oval-shaped enclosure, aligned on a roughly north-west to south-east axis, and measuring 20m by 36m. The remains of a now largely flattened internal mound was visible as a compacted surface. {2}{3}{4} The feature at this location was scheduled in April 2024. Its interpretation as a probable long barrow was supported by a geophysical survey of the site, conducted in 2018, which confirmed the presence of the continuous ditched enclosure previously identified as clearly defined cropmarks. The probable long barrow overlooks a valley with an un-named spring and watercourse that later becomes Stainfield Beck further to the west. Defined by a 'keyhole' shaped ditched enclosure, the feature is aligned north-west to south-east and has maximum dimensions measuring 20m by 36m. It is not visible as an earthwork in the landscape and recent mapping describes it as uneven and unusually shaped for a long barrow. An internal mound is visible as a compacted surface, both as soil marks and negative cropmarks on aerial photography but could not be defined from the geophysical survey. Archaeological deposits will be preserved in the spread mound, on the buried ground surface and in the fills of the ditch. These will provide rare information concerning the dating and construction of the monument and the sequence of mortuary practices at the site. The same deposits may also retain environmental evidence illustrating the nature of the contemporary landscape in which the monument was set. {5}