Cropmarks or crop marks are a means through which sub-surface archaeological, natural and recent features may be visible from the air or a vantage point on higher ground or a temporary platform. Such marks, along with parch marks,[1] soil marks and frost marks, can reveal buried archaeological sites that are not visible from the ground.
- ^ "Parch marks at Rufford Abbey (Near infra-red KAP)". Archived from the original on 2018-12-15. Retrieved 2012-12-05.