Somewhere beneath the fields of Sawyerswood in County Kildare, a rectangular enclosure lies buried and largely forgotten, visible to the human eye only from the air, and only under the right conditions. It belongs to a category of site that exists at a peculiar remove from ordinary experience: present in the ground, absent on the surface, readable only when summer heat and dry soil conspire to reveal the shadows of ancient earthworks through the uneven growth of crops above them.

The enclosure came to light on 13 July 1990, when Dr. Gillian Barrett was conducting an aerial photographic survey of the area. A photograph taken that day captured a cropmark, the telltale variation in plant growth that betrays subsurface features to a trained eye from altitude. What the image showed was a rectilinear enclosure, meaning roughly rectangular in plan, defined by two fosses. A fosse is simply a ditch, typically dug as a boundary or defensive feature, and the presence of two concentric or parallel ones here suggests some degree of deliberate elaboration in whatever structure once occupied or enclosed this ground. The date and precise character of the enclosure remain unestablished; cropmark evidence alone rarely settles questions of period or function.