A few hundred metres offshore, Dalkey Island is the largest of a small archipelago that includes Maiden Rock, Lamb Island, and the Muglins. Roughly nine hectares of grass, gorse, and rabbit-burrowed turf, it is uninhabited except for a small herd of feral goats and a noisy colony of grey seals that haul out on the rocks.
The ruined seventh-century church of St Begnet sits at the centre of the island; a squat Martello tower and gun battery date from the Napoleonic scare of 1804. Open boats run across from Coliemore Harbour in summer for a small fee — the crossing takes ten minutes and the boatmen come back when you wave. There are no facilities on the island, so bring water.