The first light here was a temporary one, installed in 1866 to plans by James Barnet, the colonial architect whose name is stamped on much of nineteenth-century New South Wales. The permanent tower came a little over a decade later. A tender was called in 1878, the stonework rose through 1879, and the lamp was first exhibited in 1880. It guided vessels into the river port and worked as a leading light, lining up with a second lamp raised on a wooden mast thirty metres away. Bring the two lights into alignment from the deck of a ship, and you were threading the safe channel between the bars. Drift off the line, and the sand was waiting.

Barnet designed the Richmond River Light as one of a family of five near-identical towers built between 1878 and 1880 along the north coast, the others being Fingal Head, the now-demolished Clarence River Light, Tacking Point and Crowdy Head. They share the same plain, confident geometry. This one is circular, a little under two metres across inside, its stone walls tapering from roughly half a metre thick at the base to thirty-five centimetres at the top. Because a pilot station stood nearby, a single keeper was enough to tend the original fixed light, a fourth-order catadioptric lamp burning colza oil, its glow visible for about twelve nautical miles out to sea.

Lighthouses are machines, and this one kept being rebuilt around its own purpose. In 1920 the colza-oil flame gave way to acetylene gas and the tower was automated, the keeper no longer needed. In November 1940 the annexe and porch attached to the tower were pulled down, leaving the bare cylinder you see today. Electrification arrived in the 1960s. The light now throws a tungsten-halogen beam and signs its presence to passing ships in a code of four white flashes every sixteen seconds, a rhythm unique enough that a navigator can name the headland from the pattern alone, even in the dark.

Most lighthouses this old have been retired into museums or holiday lets. This one still does its job. Transport for NSW keeps the light running, and the headland around it is open to anyone who wants to walk up, though the tower itself stays locked. Below it stretches Lighthouse Beach, one of Ballina's main strands, named for the small stone sentinel above. Stand on the point on a clear day and you can watch the river slide out to meet the ocean, the breakwaters now taming the bar that the light was built to outwit. The danger is mostly gone. The light keeps flashing anyway.