Construction began in 1871 at an estimated cost of £6,576 - a substantial sum, paid for in the hope of saving sailors who had previously had no warning at all. John Barr of Ardrossan won the contract for the masonry. Milne and son built the lantern and the brass mechanism that would turn inside it. The site was layered with history before the first stone was laid. Turnberry Castle had stood here in the 13th century, said by some to be the birthplace of Robert the Bruce. By the time the Stevensons arrived, only fragments remained, but the moat's outline still showed in the turf. The new tower would rise from ground that had once defended a king.

On the evening of 30 August 1873, the lamp was lit for the first time. One flash of white light every fifteen seconds, visible to ships up to 24 nautical miles offshore - the rhythm a sailor's eye learns to recognize and trust. The lantern sits 29 metres above high water atop a tapering white-brick tower. Inside, 76 steps spiral up past small rectangular windows, each one set into the curve like a punctuation mark. The iron lantern room is glazed with triangular panes and ringed by an iron railing where the keeper could stand and check the weather. Living quarters were built into the base on three sides - east, west, and south - because in 1873 a lighthouse without a keeper was as useful as a watch without hands.

For nearly a century the keepers tended the light and the families who lived in the cottages walked the cliff path to fetch supplies. Then in 1986 the Northern Lighthouse Board automated the tower, and remote-monitored it from their Edinburgh office. The cottages became, for a time, the land base for the relief helicopter that supplied Ailsa Craig lighthouse on its sheer pyramid of granite ten miles offshore. In 1992 the Board sold the accommodation block to whoever then owned the Turnberry golf course. The arrangement evolved. In 2015, the utility buildings and a bothy were leased to the resort's current owner, and in 2016 the property was renovated as holiday accommodation and a restaurant placed - somewhat surreally - next to the ninth green.

The Ayrshire Coastal Path runs right beside it. Hikers come around a bend in the dunes and there it is: a small, sturdy, almost humble lighthouse keeping watch on a stretch of water that doesn't always forgive carelessness. The light still flashes its 15-second rhythm. The shadow of Ailsa Craig sits on the horizon in clear weather. Below the cliff, the same Bristo Rock that the Stevensons declared unworkable continues to sit just beneath the surface - now warned, now seen, now safer than it was in 1869.