Though the site doesn’t appear on the 1835 Ordnance Survey maps, it shows up clearly on the 1847 revision and subsequent maps, suggesting the stonework was constructed sometime in that intervening period. The well itself was a simple affair; rough hewn stones arranged in a D shape around a natural spring, with the stones measuring about 20 by 30 by 80 centimetres each. These were reinforced by a low mound of rounded cobbles mixed with sandy, silty peat, which served the dual purpose of strengthening the structure and providing firm ground for pilgrims to stand on whilst drawing water.

The site came to archaeological attention in 2004 when excavations were carried out ahead of the N15 Bundoran to Ballyshannon bypass. What made the excavation particularly interesting was the discovery of a previously unknown burnt spread just 12 metres east of the well. This burnt deposit, likely evidence of prehistoric activity, suggests the area had significance long before the holy well was constructed. The National Roads Authority and Donegal County Council ultimately decided to preserve the well in situ, slightly adjusting the road design to protect this piece of local heritage.

By 1936, when folklorist Énrí Ó Muirgheasa recorded it as ‘Tobar a’ Seanaigh’, the well had already fallen out of use, with no religious stations or pattern days being held there. Today, no visible trace of Tobershannon survives above ground in what remains wet, boggy land. Its story exists only in archaeological records and old maps; a reminder of the countless small sacred sites that once dotted the Irish landscape, serving local communities before gradually fading from memory and use.