IICae Grugog Set back from the W side of Lon St. Ffraid at the N end of Trearddur Bay
IICraig y Mor In an elevated position on a rocky promontory, set back from the SW side of Lon Isallt and on the coastline overlooking Porth yr Afon, W of Trearddur Bay.
IIEllen's Tower (Twr Ellin) In an elevated position, overlooking the sea, c250m SE of South Stack Island.
IIPillbox in grounds of Trearddur House Located on a rocky promontory within the grounds of Trearddur House, set back from the W side of Lon St. Ffraid.
IIPorth y Castell Set back from the SE side of Ravenspoint Road, overlooking Porth Diana and c950m SW of the Church of St. Ffraid
IISouth Stack Lighthouse and former keepers' accommodation Situated on South Stack Island, due W of Holyhead, and approached via a long flight of steps in the cliff, and a bridge over the narrow strait separating the island from the mainland.
IITan-y-Cytiau In an elevated position on the slopes of Holyhead Mountain, approached from the lane that leads to South Stack Lighthouse.
IITowyn Lodge Set back from the NW side of Ravenspoint road, at the junction with Penrhyn Garw and c500m SW of the Church of St. Ffraid in Trearddur Bay.