Great South Wall

The Great South Wall (also sometimes called the South Bull Wall), at the Port of Dublin, extends from the tip of the Poolbeg peninsula more than four kilometres out into Dublin Bay. It was the world's longest sea wall at the time of its construction and remains one of the longest in Europe. It faces the newer Bull Wall, and has one of a trio of port lighthouses at its end.

Dublin Bay had a long-running problem with silting, notably at the mouth of the River Liffey, and held major sand banks, notably the North Bull and South Bull (both hard sand dry at low water), to either side of the Liffey mouth, along with the Kish Bank over 11 km out to sea. Between the North and South Bulls, a sand bar existed, rising over time, limiting access to the city quays.

Furthermore, the shape of the Liffey estuary was rather different from the present day, with the river channel not fully enclosed, much of Pearse Street (then Lazey Hill) running along the shore, which then bent sharply south, running in a diagonal to Irishtown, with Ringsend being a narrow sand spit projecting north into the bay.

Reclamation of the lands between the city and Ringsend progressed during the 17th and early 18th century, accelerated by the foundation of the Ballast Office in 1707, and by the granting of an estate there to Sir John Rogerson in 1713. Rogerson paid for a massive quay, all the way to a new mouth for the River Dodder, adjacent to Ringsend.

Years of primitive dredging were succeeded by an attempt to maintain a clear main channel to Dublin more effectively when, in 1715, the Dublin City Assembly authorised the building of an embankment from Ringsend along the north aspect of the South Bull sand bank. The first piles of what was to become the South Bull Wall were driven that year, and major work commenced in 1717, with what was then known simply as The Piles completed in 1730 to 1731. Construction involved driving of oaken piles into the boulder clay of Dublin Bay, with these anchored by baskets of gravel, and woven wattles.

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