Ffynnon Gybi is associated with St Cybi, a Welsh saint who is said to have struck a rock with his staff at this spot from which water immediately flowed.

The well was a place of pilgrimage and the waters were reputed to cure a wide range of illnesses.

The well chamber contains a sunken tank roughly 2.2m x 1.5m x 1m with surrounding walkway and niches to walls. The adjoining cottage, built to provide accommodation for pilgrims, is a single room construction, originally with an attic.