It is one thing for an ancient site to fall into ruin or obscurity; it is another for it to vanish entirely beneath a man-made lake, which is the probable fate of this spring well at Burgage More in County Wicklow.

The well was recorded in the Ordnance Survey Letters, a remarkable nineteenth-century collection of topographical and antiquarian notes compiled by scholars travelling the Irish countryside. The entry, referenced by O'Flanagan in 1928, describes a spring well situated to the west of Burgage More castle and at the foot of St Mark's Cross, a carved stone monument that still survives in the area. The well was dedicated either to St Mark or to St Baoithin, the latter an early Irish saint associated with monastic communities in the region. Holy wells in Ireland typically functioned as sites of local veneration and pattern days, gatherings where communities came to pray, leave offerings, and observe the feast day of the well's patron saint. Whether this one retained any such practice into the modern period is not recorded. When Blessington Reservoir was created in the 1940s by flooding the valley of the River Liffey, it submerged a considerable stretch of the landscape, along with whatever remained of the well's physical presence. Its exact position, if it ever sits exposed at the water's edge during periods of low water, has not been confirmed.