Head north on the M2, then take the Antrim Coast Road from Larne to Glenarm. The Castle is signposted from the town.
Head straight through Broughshane, continuing for several miles until you see the the signs for Glenarm via the Munie road on the right. At the end of this road, turn right and you will see the signposts for the Castle.
Head straight along the Coast Road, through Carnlough, until you get to the Glenarm. The Castle will be signposted.