From the air, Lake MacLeod reads as a brilliant white scar across the brown coastal plain, around two thousand square kilometres of lakebed of which only about sixty are covered by standing brine at any time. The rest is salt crust, blinding and flat, the highly reflective floor of a lake that is usually dry. The surrounding country is near-desert, and the reason lies offshore. The cool Western Australian Current sweeps up from the south, carrying chilled water all the way from the Antarctic, and that cold sea, paired with a very flat coastal plain, robs the air of the warmth it would need to make rain. So the brown earth stays brown, the salt beds glare, and the faint blue of brine pools only toward the lake's low northern end. It is a landscape of stark contrasts, painted almost entirely in three colours.

The same conditions that make Lake MacLeod inhospitable make it valuable. Because seawater seeps in and then evaporates under relentless sun, the brine here becomes roughly ten times saltier than the open ocean, so concentrated that it skips the long chain of concentration ponds most saltworks require. At the southern end, large evaporation beds yield high-quality salt and gypsum, worked by Dampier Salt, part of Rio Tinto. It is industry of an unusual kind: no drilling, no blasting, just the patient harvest of what the sun pulls out of brine that the earth delivers for free.

For all its harshness, Lake MacLeod is one of the most important bird sites on this coast. BirdLife International recognises some 382 square kilometres of its northern ponds as an Important Bird Area, and the numbers explain why. The lake hosts more than one percent of the world's red-necked stints, along with internationally significant gatherings of red knots and curlew sandpipers, shorebirds that fly astonishing distances to reach these saline mudflats. Fairy terns nest here; banded stilts, red-necked avocets, Australian pelicans and black-tailed godwits work the shallows. The brackish ponds, brutal to most life, become a vital refuelling stop on journeys that span the globe.

For all that the sea sustains it, Lake MacLeod is not entirely cut off from the sky. Every few years, rain falls heavily enough across the river catchments that feed the basin, and the lake floods with fresh water from above. That rare freshwater inundation is exactly why the lake is recognised under Australia's national directory of important wetlands: it is an outstanding example of a major coastal lake that is periodically drowned and then left to dry again. The cycle resets the chemistry, recharges the channels and lagoons, and renews the mudflats the birds depend on. Scarcity and abundance trade places here on a timescale measured not in seasons but in years.

This shoreline holds a particular place in the European history of Australia. In 1616, the Dutch navigator Dirk Hartog made the first authenticated European landing along this coast, more than a century and a half before British settlement on the far side of the continent. Early explorers recorded the extraordinary tidal ranges along these shores, the sea advancing and retreating across the flats. Long before any of them arrived, and ever since, the same slow exchange has continued at Lake MacLeod: ocean seeping inland, sun lifting it back to sky, salt left behind to glare in the heat.