Selskar Abbey is a ruined Augustinian abbey near the north end of Wexford's old town. Its surviving walls and churchyard are atmospheric rather than grand, but they give the town a visible link to its medieval past.
The site is best folded into a walk through the old streets rather than treated as a standalone excursion. Go for the texture: stone walls, uneven ground, and the sense that Wexford's long history sits just behind its ordinary shops and houses.