The remains of the Castle can be visited
CastleLarne
Olderfleet Castle

Olderfleet Castle is a four-storey towerhouse, the remains of which stand on Curran Point to the south of Larne Harbour in Larne, County Antrim, Northern Ireland. The place name of Olderfleet may be a corruption of Ulfrecksfiord (or Ulfried's Fjord), the Viking name for Larne Lough.
Source: Wikipedia · Licence: CC BY-SA 4.0 · Image: By Kenneth Allen, CC BY-SA 2.0, https://commons.wikimedia.org/w/index.php?curid=1398680
This description is an excerpt from the linked Wikipedia article and was written by its authors. Like the original it is licensed under CC BY-SA 4.0 and may be reused under the same terms.
Location: 54.8428, -5.8008