Maralinga is in Australia, in the state of South Australia.
From 1952 to 1963, the British government, with the permission of the Australian government, conducted nuclear experiments in an area of about 3,200 square kilometres at Maralinga. Seven nuclear devices were detonated, and several "minor" experiments undertaken, though in some cases the minor experiments released more contaminants into the environment than the detonations.
Maralinga is well known and very controversial for several reasons: the general fact that nuclear weapons were detonated; the coverups and misinformation between the British and Australian governments and the Australian population; the use of military personnel as test subjects; the lack of involvement of the traditional land owners; and the lack of safety standards on the site, especially in respect to nomadic aboriginals in the area, and the suspicion that this lack of safety standards was deliberate.
The British government apparently kept much of the activities at Maralinga secret from the Australian government, including the use of human test subjects - although they stressed later that they were testing the clothes, not the people.
There are reports that one of the major trials at Maralinga, Operation Buffalo in 1956, used servicemen to test the effectiveness of protective Army issue clothing against radiation, and furthermore that they either weren't aware of their participation in the test, or were misinformed of the effect radiation may have on their health.
In 1957 at Taranaki, Maralinga, the final detonation - Operation Antler - went ahead. It released a destructive force of 26.6 kilotons - much larger than the bomb that devastated Hiroshima, and the largest detonation on the Australian mainland. The effects are still being felt. Studies have found that 80% of participants and observers died before the age of 65.
The area around Taranaki was the worst contaminated site of all Australian detonations. It contained several radioactive substances including Plutonium 239 with a half life of 24,000 years, and Cobalt-60 with a half life of about 5.4 years.
Aboriginal Australians were only given the right to vote in 1967, and at the time of testing were considered sub human by the general society in Australia. In fact, it has been reported that the researchers had in depth information about flora, fauna and geological formations, and still relied on the Encyclopedia Britannica for information on aborigines.
There has been a fair amount of controversy over the involvement (or lack thereof) of the traditional land owners - the Maralinga Tjarutja (Pitjantjatjara) people - in the decision to use the land for nuclear testing. Apparently the British didn't consult the traditional aboriginal land owners before or during the research, and only one person was designated to patrol the entire area of Maralinga, to ensure that nomadic aboriginals hadn't moved onto the test site. Signs were posted, but in English - which very few nomadic aboriginals could speak, let alone read.
The Maralinga Tjarutja people were denied access to most of this land until the year 2000, when the 1996 - 2000 clean ups were completed. The clean ups were arranged after it was discovered that despite the fact that the sites were cleaned up at the end of the testing period, many areas still contained dangerous levels of radiation in the top soil, and in some cases even highly radioactive articles not more than 500m from the firing pads (articles like wire, steel plates etc). The radioactive material had been sitting there for around 40 years.
It is currently reported that most of the Maralinga area is safe for general living, though many people are still wary of believing the organisations which have been found untrustworthy in the past.
Some resources & further information:
The National Archives of Australia:
Australian Radiation Protection And Nuclear Safety Agency