It never made it onto the Ordnance Survey's historic maps, and for most of its existence it has been left to slowly flatten into the surrounding pasture. What gives it away, if you know to look, is a combination of things: the raised platform shape, the stony material that shows up clearly on aerial imagery, and a possible stone feature at its south-western end with what appears to be a linear element running toward the water. These are the hallmarks of a fulacht fia, a type of prehistoric cooking or processing site found in enormous numbers across Ireland, typically recognised by a horseshoe-shaped mound of fire-cracked stone surrounding a trough that would have been filled with water and heated using stones thrown from a fire.

The site at Tomdeely North, measuring roughly 14 metres north-east to south-west and 10 metres north-west to south-east, came to light in 1999 when archaeologist Celie O'Rahilly was walking the proposed route of an ESB power line. That kind of discovery, made not during a formal excavation but during a routine survey ahead of infrastructure works, is actually quite common in Ireland, where the density of archaeological features in the landscape often outpaces the capacity to record them. O'Rahilly flagged the feature as a possible fulacht fia on the basis of its morphology and its proximity to the stream, both of which are typical of the type. The monument was later confirmed as visible in aerial and satellite imagery, appearing as an irregular oval-shaped stony area on Digital Globe orthophotos from 2011 to 2013 and on Google Earth images from April 2015. The record was compiled by Alison McQueen and Vera Rahilly and uploaded to the Sites and Monuments Record in July 2020.

The site lies in low-lying, poorly drained pasture approximately 400 metres south of the Shannon Estuary, with a tidal stream running close to its western side and a gallops track sitting about 15 metres to the east. The working landscape around it, part agricultural, part equestrian, gives little indication that anything prehistoric is present. There is no formal access or signage, and the ground is likely to be soft underfoot for much of the year. The clearest view of the feature's outline is, in fact, from above, using freely available satellite imagery, where the stony oval platform is legible in a way it simply is not at ground level.