On a slight south-facing slope, aerial photographs show the faint cropmark of an oval enclosure, roughly 40 metres across its longer axis and between 25 and 30 metres on the shorter. Cropmarks form when buried features such as ditches or banks influence the growth of overlying crops, producing subtle variations in colour and height that become legible from altitude. Here, the mark traces what appears to be a continuous fosse, a ditch running around the perimeter of the oval, though the ground at surface level gives almost nothing away.

What makes the site genuinely puzzling is the uncertainty over what it actually was. A rath, the most common type of early medieval enclosed farmstead in Ireland, typically defined by one or more earthen banks and ditches, sits about 280 metres to the north. The proximity might suggest a connection, but the Assagart enclosure carries an alternative interpretation: it may have been a decorative tree-ring, a planted circle of trees whose root disturbance left the ditch-like mark now visible from above. That reading would make it a relatively modern landscaping feature rather than an ancient settlement, and it is a reminder that not every cropmark resolves into archaeology. The two possibilities sit uneasily alongside each other, and without excavation, neither can be confirmed.