Holyhead Breakwater

[1] In the age of sail, northerly winds in the Irish Sea could often prevent ships from Ireland entering the old harbour at Holyhead.

When adverse weather conditions halted sailings from Holyhead, passengers and cargo had to be moved to Porth Dafarch on the southerly side of Holy Island.

Construction included the Admiralty Pier (built 1810-24) by John Rennie and the South Pier (built 1823-31) and graving dock designed by Thomas Telford; his London-Holyhead Road, which included the Menai Suspension Bridge and Stanley Embankment, ended at Admiralty Arch on Salt Island in Holyhead.

The heavily-used Admiralty Pier (for the mail and Packet trade) at the northern end of the old harbour (and attached to Salt Island) often took the brunt of bad weather which required frequent repairs and dredging.

Poor weather delaying sailings from Holyhead was no longer acceptable because of the number of passengers and cargo crossing between Ireland and Great Britain.

[4] Shaped 10-tonne blocks of limestone were used to create an outer facing wall, thereby encasing a rubble mound raised from the sea both by dumping from ships and tipping from the shore.