What makes this site in north County Dublin remarkable is precisely its invisibility: the only way it announces itself is from the air, where the parched or ripened grass of a crop field outlines two circular enclosures that have otherwise vanished entirely from the surface of the landscape. These shapes, known as crop marks, form when buried features such as ditches or banks alter the moisture content of the soil above them, causing the vegetation to grow or ripen at a slightly different rate to the surrounding field. The result, invisible at ground level, becomes legible from above as a ghostly diagram pressed into the earth.

The site consists of a larger circular enclosure with a smaller one attached to its northwest side, a configuration sometimes associated with early medieval settlement in Ireland, where a primary enclosure might contain a dwelling or farm complex and an annexed enclosure served a secondary function such as housing livestock. A separate enclosure lies to the west within the same field, catalogued in the Sites and Monuments Record as DU005-098, suggesting that this part of Baltrasna was once a more complex and populated place than its current agricultural appearance implies. The information on record draws on the SMR file and a personal communication from T. Condit, and was compiled by David O'Connor. The site sits within a gently undulating, relatively low-lying stretch of ground, with open views northward toward the sea.

Because the enclosures exist only as crop marks, there is no upstanding monument to seek out. The best time to observe such features, even in photographs, is during dry summers when differential growth in cereal crops is most pronounced. The field itself lies in ordinary farmland, so access is a matter of following public routes and respecting working agricultural land. The aerial photographs held by the relevant heritage bodies are the most direct way to engage with what is actually here, and consulting the Sites and Monuments Record entry gives a clearer sense of how this site fits within the broader archaeological landscape of the area.