The place
At Castletown, an earthwork mound supports the remains of the later castellated house known as Byrne's Folly. The official tourism account dates that house to 1780 and locates the site on Mount Avenue, around two kilometres from the centre. The place is also strongly associated with Cú Chulainn in local mythology. These are different kinds of history: the standing ruin is a later building, while the legendary connection expresses how the landscape has been understood and retold. It should never be illustrated as a surviving palace of the legendary hero.
What survives, and why it matters
A layered place where Dundalk's name, legendary identity and later built landscape meet.
Follow the sources
Research checked 17 October 2026.