The grey granite that built much of nineteenth-century Dublin — including the great harbour walls at Dún Laoghaire — was cut out of the side of Dalkey Hill here. After the quarry closed it filled with scrub and became a public park; the long flat-bottomed pits, the spoil heaps, and the funicular incline that once carried stone down to the harbour are all still recognisable in the landscape.
The high vertical faces are now the most popular rock-climbing venue in Ireland, with hundreds of named routes graded from beginner to severe. Even if you do not climb, it is an unusual place to walk: spires of granite, gorse-yellow slopes, and the sea suddenly appearing through gaps in the cliff edge.