Ulysses opens on the roof of a Martello tower at Sandycove, and you can stand on that exact roof for nothing — which makes this the most accessible piece of literary pilgrimage in Ireland. The walk pairs the tower with the cold-water swimming culture below it and the seafront back to Dún Laoghaire.
Four kilometres, best in the morning. Start at the James Joyce Tower, one of the squat coastal forts thrown up against a Napoleonic invasion that never came. Joyce stayed here a handful of nights in 1904 and put it on the first page of the century's most argued-over novel. Go up; the gun platform on the roof is open and free.
Below it, the Forty Foot — two hundred years of sea swimming, once men-only and bare, now everyone's. Watch the regulars take the steps without flinching. Round to Sandycove's small harbour and beach, then north along the Scotsman's Bay promenade, the bay open the whole way, the granite piers of Dún Laoghaire growing ahead. End at the harbour and the DART, the tower and the cold water behind you.