Queensland had only just become a colony in its own right, separated from New South Wales by Queen Victoria's signature in 1859, when the need for navigation aids here became urgent. A pilot station went up on Cape Capricorn as early as 1861, though it was shifted to Grassy Hill three years later; the case for a proper light on the cape never went away. The first real lighthouse followed in 1875, a classic Queensland design: timber-framed, clad in iron, prefabricated in Brisbane and shipped north. The plans came from the office of the Colonial Architect, F. D. G. Stanley. The build was almost comic in its mishaps. A last-minute change to the lantern order from England meant no lamp room had been provided at all, forcing an urgent improvised one of timber and iron plate. When it finally lit, the lamp was an oil wick burner, a small flame doing an enormous job, with two auxiliary lights set to the north and southeast to fix the safe line through the channel.

Everything the station needed came the hard way. Supplies sailed up from Rockhampton by steamboat to the foot of the hill, then had to be hauled more than ninety metres up a steep tramway, hand-winched crate by crate. An inspector in 1912 recommended steam winches, stronger light, repaired dwellings, then watched his advice get followed slowly and only in part. Not until 1923 did the light source improve to an incandescent kerosene mantle. Life here was measured in deliveries and weather. The keepers and their families lived at the edge of the continent with the sea as their only road, and a single missed supply run could mean weeks of going without.

The lighthouse you would see today is the third on the spot. A concrete-block tower replaced the timber one from plans drawn in 1937, and the current squat concrete structure, just 6.4 metres high with chamfered corners and a small porch, dates from 1964. Around it stands a whole vanished way of life rendered in corrugated iron and white-painted cottages: a powerhouse, a winch house, a store, even a still-working rail line of steel tracks running down to the beach with its timber trolley. In 1988 the light went solar and the keepers went home for good. Its original lens, the glass heart that once threw the warning out to sea, now sits on display at the Townsville Maritime Museum.

Cape Capricorn now keeps a quieter watch. Its light still flashes white and red every five seconds, powered by solar panels and managed remotely by the Australian Maritime Safety Authority, while the surrounding land falls within Curtis Island National Park. The tower itself is closed, and the only ways to reach it are by boat or helicopter. Yet the old keepers' cottages have found a second life as holiday accommodation, so it is still possible to sleep on this headland, wake to the same horizon the lightkeepers scanned, and stand with one foot on each side of the tropic line that gave the cape its name.