Viscount Montgomery's harbour (1626; improved 1640), superseding what had hitherto been probably only a small jetty, was built and maintained as a result of the Royal Warrant of 1616 which limited travel between the Ards and the Rhins of Galloway to this port, and that at Portpatrick also owned by Montgomery.

Much patched and decrepit, the quay was virtually rebuilt, though along the original line, between 1775 and 1785 by the landlord, Daniel Delacherois, probably with the help of John Smeaton, the distinguished civil engineer who had apparently made earlier more elaborate plans for extending the harbour, and who had just rebuilt Portpatrick harbour.

The initial plans and surveys for this ambitious undertaking had been made by John Rennie Senior, the celebrated engineer whose works included Waterloo, Southwark and London Bridges over the Thames.

He had as his resident engineer a fellow Scot, the seasoned marine builder, David Logan, who had assisted Robert Stevenson at the Bell Rock Lighthouse (1807–1810).

This 'Anglesea marble' lends itself to the finest ashlar dressing and the new piers remain a triumph of stone carving.