Capel-y-ffin (Welsh for 'chapel of the boundary') is a hamlet near the English-Welsh border, a couple of miles north of Llanthony in Powys, Wales.

On the other side of the River Honddu is a small, whitewashed Baptist chapel built by the two brothers, William and David Prosser.

[4] In 1869, Joseph Leycester Lyne, self-styled "Father Ignatius", purchased 32 acres (130,000 m2) of land at Capel-y-ffin in order to build an Anglican monastery near the ruins of Llanthony Priory.

With the help of fellow monks and local masons, he succeeded in building 'Llanthony Tertia', where an eccentric version of monastic life – witnessed by Francis Kilvert – continued till his death in 1908.

[7] In 1880, Lyne's religious convictions were confirmed by visions of the Virgin Mary seen in the monastery and nearby fields by monks and local farm boys.