The Black Valley is a strange region inhabited by stranger folks, home to a number of disaster sites and ancient ruins. One of these is the Sambarra Crater, located in relative proximity to the Blackburn Disaster Zone. This crater is extremely irradiated, and according to official documents, was formed as part of the 1958 Blackburn Disaster. Those who live here may attest that the explosion occurred three years later than the Federal Government claims. In reality, the Sambarra Crater was once Beta Base, home to Project GREYMAN. During the Oceanykan Revolution, many of the project's members defected and formed the Australian Emergency Committee. In the ensuing covert conflict, federal forces sought to capture Beta Base, but the installation's self-destruction mechanism was manually activated, and a cobalt bomb blew it up. However, the blast yield of a cobalt bomb (designed to maximise radioactive fallout as opposed to blast energy) was severely over-estimated, and many of the underground levels remained intact, not taking into account seismic damage. This was deemed a successful operation by the AEC, since radiation levels at the Sambarra Crater were, and are, enough to induce lethal Radiation Sickness within minutes.
Since then, many explorers have ventured down to the ruins of Beta Base to retrieve classified documentation and prototype equipment. However, radiation levels are so high that only extremely well-equipped explorers with full-body NBC suits and closed-loop respiration systems could ever hope to go down and come out unscathed. In addition, the hardiest of mutants from the Blackburn Disaster Zone have made of the ruins of Beta Base their new home, protected from human hunters by the lethal radiation, to which they are partially immune. Finally, as the law could never hope to reach this place, it is not rare for explorer parties to shoot each other in hopes of retrieving whatever the other side has managed to pillage.