The harbour sits where the Glenarm River meets the sea, a small marina of moored boats with the wooded river glen rising behind it and the castle demesne off to one side. This is the southernmost of the nine Glens of Antrim, on the coast between Larne and Carnlough, and the cliffs above it are white — Ulster limestone, chalk, which shapes the whole shoreline here. The name is from the Irish Gleann Arma, valley of the army.
You reach it along the Antrim Coast Road, the A2, part of the Causeway Coastal Route. William Bald engineered it between 1832 and 1842 by blasting the cliff faces to carry the road along the shore — "30,000 cubic yards of rock have been hurled down on the shore almost entirely by blasting," as Bald himself put it. Belfast is about 25 miles south, Larne twenty minutes, and the nearest railhead is Larne; there is no station in Glenarm. Translink buses run the coast corridor between Larne and the Glens.
For dinner the pick is Moran's on Toberwine Street, a seafood-led kitchen ranked first of the three places to eat in the village. Lobster, scallops, local halibut and a garlic seafood chowder the kitchen is happy to call famous; one visitor summed it up as "first class food at reasonable prices." It is dine-in only and bring your own beverage, so pack a bottle. The Bridge End Tavern, down at the bridge, keeps a good pint and a reputation as "a lovely, friendly, little pub."
Most of the daytime eating clusters around the walled garden at Glenarm Castle. The Tea Room, run by chef Sean Moran, serves the estate's own Glenarm Shorthorn beef and organic salmon. The Potting Shed pours coffee from Ground Espresso Bars in a woodland setting and lays on dog showers and pup cups. The Milk Parlour turns the estate's Shorthorn herd milk into small-batch ice cream — White Chocolate and Amarena Cherry, Captain Morgan's Rum and Raisin — and the Pizza Pavilion does sourdough pizzas from a wood-fired oven. The garden is open to the public from roughly May to September.
Glenarm Forest occupies the old 800-acre demesne, three waymarked routes through oak, ash, beech and conifer. The Red route is two miles, the Blue one, and the Yellow a half-mile riverside stretch. Wear proper footwear — the paths climb and descend and turn slippery. The river runs dead straight down the centre of the glen, holding brown trout and salmon, with herons, kingfishers and otters along it and red squirrels in the trees. Look for The Lead, a nineteenth-century water channel dug to feed a whitening mill that has otherwise gone.
St Patrick's Church dates from 1763 and stands on the site of a Franciscan friary. Its churchyard holds a mass grave from the 1854 cholera epidemic, which began at the Bridge End Tavern and killed a large share of the village. The McDonnells have held the estate for around four centuries and occupied Glenarm for closer to six.
The castle's Barbican gatehouse, its landmark tower, was restored by a conservation trust and now takes guests of its own. Children still cross it free into the walled garden all summer.