Boasting one of the worlds finest harbours, Dún Laoghaire takes it's name form the great King Laoire who in 480A.D. maintained a great "Dún" or stone fort in the centre of the town. The ancient fort was demolished in 1803 to make way for the building of a Martello tower which in turn was replaced in 1834 by the first suburban railway in the world. King Laoire's large garrison ensured that the Romans would think twice about invading Ireland from British shores. Some say that Patrick the boy shepherd arrived at Dún Laoghaire as a slave, it was the same Patrick who returned in 432A.D. to face King Laoghaire and who subsequently destroyed his ancient Druid order. Traces of this order can still be found in Dún Laoghaire and the neighbouring village of Dalkey. Both towns are closely linked for it was the granite from Dalkey Hill that built Dún Laoghaire harbour in 1817.
The decision to build a harbour in what was until 1817 a small fishing village came about as entry into the River Liffey was becoming more and more difficult, with ships having to wait days before they could berth and off load their cargo. The amount of shipwrecks was also becoming unacceptable, literally hundreds per year being wrecked off the coast of Blackrock and Monkstown with thousand of lives lost, which eventually led to the setting up of the lifeboat station in 1803.
So it was in 1817 that the Earl of Whitworth laid the first foundation stone of the pier designed by John Renny. Designed to be a port of refuge away from the fierce Irish Sea where large ships could berth safely it would have worked had the Earl not insisted that the entrance to the harbour be widened to accommodate the Admiral's fleet. This widening of the harbour also accommodated the silt from the surrounding shoreline which washed in and made it impossible for the larger ships to enter safely as planned. Despite this the Mailboat operated out of DúnLaoghaire successfully carrying cargo, passengers and of course, Mail.