Great Southern Walk nears completion with a new 405-step staircase at from Bald Hill to the beach

Work has just been completed on the stairs, one of the missing links in the 67km track, giving walkers a safe way down from the southern edge of the Royal National Park.

When complete the walk will extend from Kurnell in Sydney, along the coast track through the Royal National Park, up the Illawarra Escarpment and to Sublime Point at Bulli Tops.

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Minister for the Illawarra Ryan Park hailed the National Parks and Wildlife Service workers who built the giant staircase using some 150 tonnes of stone flown in by helicopter.

"This is a simply stunning walk which will eventually link Botany Bay with the Illawarra," he said at Bald Hill on Friday.

"It features some of the most spectacular coastline and natural environments our state has to offer and I'm so pleased to see this first stage completed.

"The work that went into completing this first stage, which plunges down the escarpment, was simply phenomenal.

"The new walking track provides local residents with safe pedestrian access to Bald Hill lookout and delivers much-needed pedestrian access from Stanwell Park train station to this popular tourist destination."

From the beach the Great Southern walkers then join the Wodi Wodi track behind Stanwell Park train station.

Environment Minister Penny Sharp said this was a vital link.

"For the first time, these two popular conservation reserves are connected by a walking track, offering a world-class bushwalking experience right on Sydney's doorstep," she said.

The last two links are a section between Otford and Bald Hill, and between Bulli Tops and Sublime Point.

Camp grounds would be established in addition to those already along the track and there was talk of an overnight option at Bulli Tops being explored.

Graham Burgess, president of the Illawarra National Parks Association, said the walk would be "amazing".

"The work the NSW National Parks and Wildlife Service is doing is great for visitors and locals, who now have a safe pedestrian connection up and down the hill," he said.