Great Irish Coast | The Bull Walls and Poolbeg Lighthouse

The iconic red lighthouse at the end of the Great South Wall is a welcome sight to visitors entering Dublin Port from overseas. And from the land, the lighthouse and the seawalls are a hugely popular destination for people to take in some fresh sea air and unique perspectives of Dublin.

They also form an important piece of the maritime history of Dublin Port and have played a role in the formation of one of Dublin’s most important nature reserves.

Poolbeg Lighthouse and the Great South Wall

The Great South Wall 

Dublin Bay and its port was for centuries particularly dangerous for ships to navigate. It was wild, exposed to the wind, prone to storms and shipwrecks were common. The hazardous conditions forced seafarers to seek shelter at Clontarf until it was safe and the wind conditions favoured entrance to the port. Silting was another serious problem and it required constant dredging.

In 1716, work began on a bank to protect and provide shelter for incoming ships and to prevent the build-up of sand coming into the river channel. Early efforts included creating a barrier by driving piles into the seabed but this was breached by storms. Work began on the construction of what we now know as the Great South Wall in 1748 and it finished in 1795. It was an incredible feat of engineering and at the time it was one of the longest seawalls in the world.

 Tall ship Phoenix passes by Stena Line ferry on way into Dublin port

Today, it remains one of the largest in Europe extending out over 1.5km from Ringsend. On a clear day, the walk out to the lighthouse commands unrivalled views of Dublin Bay from Dun Laoghaire Harbour all the way round to Howth Head and it’s the perfect place to watch the ships sailing into the port.

poolbeg lighthouse

The iconic red Poolbeg lighthouse at the end of Great South Wall

The Poolbeg Lighthouse

In 1761 work began on a lighthouse at the end of the wall and it was operational in 1768. Today the lighthouse is unmanned and is one of three in the vicinity, another is at the end of North Bull Wall and a third sits out in the bay.

In their earlier maps up until 1958 Ordnance Survey Ireland used the low water mark of the spring tide on 8 April 1837 at the Poolbeg Lighthouse as a standard height for all its maps.

The North Bull Wall

In 1800, a major survey of the harbour was carried out by Captain William Bligh, most notably remembered for his role in the mutiny on the HMS Bounty. Upon his recommendation, a second wall was built parallel to the South Wall to improve the entrance to the port and to prevent sand building up in the mouth of the harbour.

Wooden Bridge to North Bull Island, Dublin

A wooden bridge was erected in 1819 to facilitate the construction of the stone wall proper. The stone wall began construction in 1820 and was completed in 1825 and it’s just under 3 km long. A lighthouse was erected at the end in 1880.

North Bull Wall, Clontarf, Dublin

The Formation of Something Special – Bull Island

Over the next 50 odd years, the two walls working in tandem allowed the natural tidal effects to successfully deepened the entry to the port. The sand was now being deposited on the North Bull and an island began to emerge.

The creation of this new island was its own reward and today Bull Island is an incredibly important part of the Dublin Bay Biosphere and has several nature conservation designations including as a National Bird Sanctuary, a National Nature Reserve, a Special Protection Area under the EU Birds Directive, and a Special Area of Conservation under the EU Habitats Directive. It’s home to hundreds of bird and plant species, is an important wetland and wintering site for visiting birds. 

Winter visitors. Brent Geese flock to Bull Island

Brent flying over Bull Island, Dublin

Following the outbreak of the First World War in 1914, the British Army commandeered the island for military training. The island was primarily used as a firing range but also for training in trench warfare and the Royal Dublin Golf Club clubhouse was used as officers’ quarters.

Dollymount Strand

Today the island remains an excellent amenity with for a number of different activities. It’s a fantastic walking spot, has it’s own golf course and it’s popular beach Dollymount Strand is perfect for kitesurfing and water sports.

Volunteers North Bull Island Programme

Kite Surfer at the Battle of the Bay festival that takes place during the summer

About the Author

Ann Robinson
Has a passion for coastal heritage and maritime history. Loves sharing the best of the Irish coast online. Contact me or follow me on Twitter @AnnRobinson22