It always surprises me how few #Dubliners have done this, or even know where it is, but out past the old Pigeon House fort and beyond the #Poolbeg Power Station is The Great South Wall - a sea wall built around 1750 that juts about a mile out into Dublin Bay. A walk to the lighthouse at the end and back will blow any cobwebs off, with an amazing view of the city, mountains and bay to boot. Taken from: VisitDublin