From broken ginger beer bottles to World War II air-raid shelters, archaeologists involved in the construction of Sydney's new light rail have unearthed more than 37,000 artefacts along the 13-kilometre route, which has been one of the city's main thoroughfares since settlement.

Key points: Chinese barrel jars and an 1850s anchovy paste jar among thousands of artefacts uncovered during light rail construction

Chinese barrel jars and an 1850s anchovy paste jar among thousands of artefacts uncovered during light rail construction Tram tracks salvaged from Sydney's former tram network found along Anzac Parade in Kensington

Tram tracks salvaged from Sydney's former tram network found along Anzac Parade in Kensington Indigenous heritage consultants dismayed at the destruction of what they say is an important Aboriginal site

"The remains we're dealing with, they're part of Sydney's history," heritage consultant Jayden van Beek said.

"They're part of our heritage so it was important to make sure that was all managed correctly and everything was investigated and recorded.

"Quite a lot of our work has been in the road corridors. Typically there's been less development through there, so what we have found in those places tends to be evidence of the development of Sydney's utility network."

That includes convict-era pavers from the 1820s, but more commonly found items were ceramic and glass fragments, including an 1850s anchovy paste jar from England and glass soda bottles.

Rarer finds were pieces of Chinese barrel jars from a late 19th-century merchant shop on George St.

One of the largest discoveries was a 30-metre-long World War II zig-zag trench built at High Cross Park in Randwick. Dating back to 1942, it's one of many such shelters built by local councils in open spaces that were filled in once the war was over.

"Individual artefacts on their own may not reveal too much," Mr van Beek said.

"They may have interesting stories but it's more about the collective assemblage, and that may provide information on what items were available, what people were choosing to purchase, where these items were coming from."

About 150 metres of old tram tracks salvaged from Sydney's former tram network were found along Anzac Parade in Kensington.

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They're now being used to run vintage passenger trams in the Royal National Park.

"It's been so important for us to preserve the history and to reuse it wherever we possibly can," Marg Prendergast from Transport for NSW said.

"It's heart-warming to think parts of the old tramway rails from Anzac Parade heading into Ascot Street that led to the original Randwick Racecourse — which is now the site of Randwick Stabling Yards that houses Sydney's new tram fleet — have a new home at South Hill where vintage trams are gliding over them again."

But Indigenous heritage consultants are dismayed at the destruction of what they say is an important Aboriginal site.

Scott Franks from consultancy Tocomwall said more than 2,500 valuable stone and glass artefacts were discovered near the new tram stabling yards in 2016.

The find prompted a failed bid to stop work on the project.

"The site should have been left in situ and left intact, left alone. It should have been properly recorded and then used as an educational site," Mr Franks says.

The mid-19th-century sandstone base of Alison Road, Randwick. ( Supplied )

"That's now been lost. It goes from an archaeological deposit, to plastic bags locked away in an office somewhere that no-one can access."

A spokesperson for Transport for NSW said: "Chemical analysis was carried out on a sample of the stone items last year and revealed some of the stones were made from a type of flint likely originating from the banks of London's River Thames, indicating that the Aboriginal people took, or were given, the stones and manufactured some traditional tools.

"We continue to work with our heritage experts and aboriginal stakeholders to ensure the best outcome for this find."