For many years, Ffynnon Leinw was thought to be the 'flowing well' mentioned by Gerald of Wales in 1191, a spring which rose and fell with the tides. Camden mentioned Leinw some 400 years later, but doubted the story, and Lhuyd, while making note of the well mentioned no special qualities. But Pennant, a Flintshire native, was happy to accept that there may have been some truth to the , 'flux and re-flux' of the well, and Samuel Lewis in 1833 was a bit giddy in writing about Leinw, stating that its healing qualities were the 'equal if not greater' than St Winefride's. A visit by the Royal Commission at the beginning of the 20th century found it dry, while at the end of the century it was full to the brim. In the summer of 2020, however, it was empty and heavily overgrown, though a rather curious fissure in the well basin had some standing water within it. This area of Flintshire was heavily mined, and Cilcain even saw a brief and bright gold rush in the hill above the well, so its likely that the well was affected by the work. But it was clearly important to the community, its reputation perhaps obscured by its likely mistaken connection to Gerald's flowing well, since it is big - the well basin is some 18 feet by 10 feet, and 2-3 feet in depth. The walls are crumbling now, and slowly being consumed by nature, as are the steps into the basin. Though close to the main Mold to Denbigh road, it feels as if it is slowly being swallowed by time.