The Paroo is the last unregulated river in the entire Murray-Darling Basin - no dams, no weirs, no engineered certainty. It flows when it flows, on its own terms, and most of the time it does not flow at all. This wildness is the whole point. The wetlands here, the Peery and Poloko lakes and the floodplains around them, are shaped by feast and famine: long dry spells punctuated by floods that may not come for years. The plants and animals are adapted to exactly this unpredictability. Where the Paroo finally meets the Darling - the Baaka - the park protects a stretch of country that engineers elsewhere long ago smoothed into reliability. Here, reliability was never on offer, and that is why it still teems with life.

Beneath this dry country lies the Great Artesian Basin, an ocean of ancient water trapped in rock. In a few rare places that water finds a crack and pushes to the surface, and as it evaporates it leaves behind salts and sediment that pile slowly into mounds. These are artesian mound springs, and they are reckoned the rarest landform in Australia. Almost all of those in western New South Wales have died, their flow lost as the basin's pressure dropped. But at Peery they survive - the largest active mound spring complex in the state, and the only springs in NSW found on a lakebed. The salt pipewort, one of the rarest plants in the state, grows here and almost nowhere else, clinging to this one improbable source of permanent water in a land of drought.

Long before pastoralists carved the land into the runs of Peery, Mandalay and Arrowbar, this was - and remains - Paakantyi country, the people of the river also known as Barkandji. Their connection here is not a relic but a continuity, written into the land in hearth sites, scatters of stone tools, and trees still scarred where bark was carefully taken. The mound springs at Peery were a secure and lasting source of fresh water, and they live in the stories of this place. That knowledge has not been set aside. The park is managed in partnership with the Paroo-Darling National Park Elders Council, and the controlled burns carried out here are deliberately patterned after the way Aboriginal people tended this country for generations - caring for it as people whose relationship with the land is ongoing, not ended.

Most of the park falls within an internationally recognised bird area, and in the right conditions the reason becomes overwhelming. When the lakes fill, waterbirds gather in numbers that defy the surrounding emptiness, breeding and feeding while the water lasts. Across the wider landscape of grey cracking clays and red sand hills, red kangaroos and three kinds of grey-toned macropods move through the mulga; 424 plant species have been recorded across the park's gorges, dune fields and lake basins. It is a place of extremes - extremes of heat, of drought, of sudden abundance. Reached only by dry-weather roads from White Cliffs or Wilcannia, it asks patience and rewards timing. Come in a wet year and you will not believe the desert can hold so much life. Come in a dry one and you will understand why every drop of that artesian water matters.