06-05-2025
The little-known Aussie paradise where it's only safe to stay for one hour
An isolated chain of islands off the Western Australian coast with incredible snorkelling, diving and fishing is touted by the state's tourism department as one of its 'best kept secrets'. And while many Aussies have never heard of the Montebello Islands, those that are familiar with them may be hesitant to visit due to the islands' explosive history — and we mean that quite literally.
The little-known destination is made up of more than 170 islands spanning across 58,000 hectares, and was the site of three nuclear weapons tests by the British military in the 1950s. One of the tests, named Mosaic G2, was the largest nuclear explosion ever recorded in Australia with contamination found as far as Rockhampton in Queensland.
On some islands, visitors are recommended to limit their stay to no more than one hour due to radiation still being present. The remnants of buildings, cars and bunkers remain, but tourists are advised not to remove any relics and to avoid kicking up soil or dust which may contain radioactive particles.
Initially, Margie Dizon was 'scared' to visit the islands after reading about their nuclear past. The psychologist from Darwin and her partner Ricky Harris love to explore Australia, and visit the Kimberley every year.
Last year, when someone recommended the pair visit the Montebello Islands, Margie said she was immediately sceptical about visiting the 'nuclear wasteland'.
'The Montebello Islands were admittedly a scary thing for us, because they were the site of those nuclear tests. And we're not talking about just the one test, they did three,' Margie told Yahoo News.
'How do I know what islands are safe, which are not safe and so forth? It was really hard, actually, selling the idea to myself.'
But after months of careful planning and gentle persuasion from Ricky, the pair set out on their boat with $3,500 worth of fuel and made the three-hour trip out to the islands — where everything soon changed for Margie.
Margie and Ricky spent hours everyday exploring new islands, snorkelling, fishing and diving. They would eat fresh seafood straight from the ocean, including fish, crayfish and squid, and sleep on their boat every night. The pair documented the journey on their YouTube channel.
'I didn't think I would say it, but I'm in love with it,' Margie laughed. 'What changed it for me was the marine life. In the end, Ricky and I almost stopped fishing. We would just catch one fish to have for dinner, but the rest of the time we didn't want to fish anymore because it was just so beautiful.
'It was just teeming with life and big fish. You can choose to spear, or you can just watch. We chose to just watch. It was amazing.'
They even visited 'ground zero', the islands where two of the detonations occurred in 1956. Margie said she only stayed on the island a matter of minutes but Ricky got a little closer to a plaque that signals where the bomb was detonated.
The first weapon to be tested in the Montebello Islands was an atomic bomb that was detonated in 1952 on a Navy ship moored near Trimouille Island. The other explosions took place on Trimouille Island and Alpha Island, both in 1956.
After spending eight days at the Montebello Islands, Margie and Ricky were sold — it had quickly won their hearts to become one of their favourite destinations in Australia. After their first trip last year, the couple soon headed back to stay for another month. Then earlier this year, they returned again for another eight days.
'Montebello Islands changed my life,' she said, adding she used to be terrified of diving and would have panic attacks under the water.
'Now I dive every possible chance I get. And I'm a psychologist, I treat people with phobias. For so long, I couldn't treat myself until I just let go.
'It was so beautiful, you cannot focus on anything else. I think with this particular place, you just switch off and there's nothing but you and fish and marine life in front of you — Oh! and a radioactive island!'
Even 73 years after the first weapons test, elevated radiation levels are still present on the islands.
Madison Williams-Hoffman, PhD candidate in environmental radioactivity at Edith Cowan University, has studied radionuclides (isotopes that give off radiation) in the Montebello Islands for the past six years. She told Yahoo News they will remain in the area 'for a very long time'.
'There are still areas that have higher radiation levels than others, so in the areas where those levels are highest it is recommended that you limit the amount of time you spend there,' she said.
'It's similar to when the UV index is very high, you are recommended to protect yourself and one way you can do that is to limit the amount of time you spend in the sun to protect you from the UV radiation.'
Williams-Hoffman said other studies have found that radionuclides are even present in the fish around the islands, although the levels are 'very low' and don't pose a threat to people who have eaten them.
She implored all visitors to respect the guidelines in place on the islands, including following the one-hour time limits and leaving the soil and relics undisturbed.
"There really aren't that many (rules) — they wouldn't impact your trip there otherwise, and they're not hard to follow,' she said.
For those with more questions about radiation, Williams-Hoffman recommends ARPANSA's Talk to a Scientist team.
'A real scientist will get your questions and will be able to give you an answer or point you to where you need to go. It's a fantastic program.
'Radiation science can be complicated, so I'd just recommend getting your facts from the experts rather than TikTok or YouTube personalities.'
For more information about the Montebello Islands, including a map of the elevated radiation areas, check out the visitor guide here.
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