St Brigid's Well is a small pilgrimage site near Kildare associated with one of Ireland's most important saints. It is a quiet stop rather than a large attraction, but the well, devotional objects, and rag tree make it an atmospheric place to understand local religious practice.
The traditional custom is to dip a cloth in the water, touch it to an afflicted part of the body, and leave the cloth on the tree. Even if you do not take part, visit respectfully; for many locals this is still a place of prayer.