SCIENTISTS have finally cracked the ancient mystery of 1,400-year-old “alien rings” rising from the hills which were fuelling a tirade of conspiracy theories.

Locals had been puzzled by the series of bizarre rings scattered around Melbourne, Australia, and thought they were the work of aliens or a natural phenomenon.

But now, scientists have revealed they are actually ancient monuments crafted by Aboriginal people called the Wurundjeri Woi-wurrung – the traditional owners of the land.

Their findings were described in a new study published in Australian Archaeology.

Researchers estimate there were once over 400 of these structures across New South Wales and Queensland in eastern Australia, but only around 100 remain today.

Far fewer have ever been discovered in the southern-most state of Victoria, but the five around the town of Sunbury are amongst them.

Many other rings of this kind are thought to have been destroyed by European settlers when they colonised the land.

It is believed the ancient people would dig out earth and build it into mounds that formed the large circles, hundreds of metres across, that are still visible today.

It is also now understood the circles continue to be very important historically and culturally to Aboriginal people today.

Elders of the Wurundjeri Woi-wurrung culture explained that the rings are used to reflect on themes including the European occupation, colonisation, self-determination, adaptation and resilience of the people.

Previous studies had indicated that the sites were associated with sacred locations, but had not unearthed any of the cultural value now understood.

The Wurundjeri Woi-wurrung people led a new archaeological excavation of one of the rings, known as Sudbury Ring G, in 2022, which has allowed these new revelations.

Ring G is thought to be a ceremonial meeting spot for Aboriginal ancestors and was first excavated in 1979 by archaeologist David Frankel.

Some 166 artefacts were unearthed in this initial dig, and Wurundjeri Woi-wurrung people also led the re-analysis of these.

This involved dating the ring deposits to estimate when it was created, and studying wear patterns to understand how the ancient people used stone tools.

The study revealed that the ring was constructed somewhere between 590 and 1,400 years ago.

It showed that the people spent time in the area clearing the land and plants, scraping back soil and layering rocks.

They also lit campfires, made stone tools and moved items around in the ring’s interior.

Wear patterns and residues on some of the tools suggest Woi-wurring people people may have used them to to create feather adornments and scar human skin for ceremony and decoration.

The scientists behind the study said in Live Science: “[the research] expands our understanding of the richness and diversity of Australia’s archaeological record, created over more than 65,000 years of continuous occupation by Aboriginal and Torres Strait Islander peoples”.

They added: “[The study] demonstrates the importance of further investigating and preserving these earth rings, as well as others known to occur across eastern Australia.

“This is especially important in the face of continued threats by land development and climate change which threaten the survival of earth rings.”