Project 4.1
In 1994, a 1953 "Castle Bravo" program prospectus was found which included reference to Project 4.1 apparently written before the "Bravo" shot had occurred. The U.S. government responded that someone had gone back into the project list after the "Bravo" test to insert Project 4.1; thus, according to the U.S. government, the acts were not premeditated. All other U.S. documents point to Project 4.1 having been established after the "Bravo" test—most sources point to its having been organized on March 7, 1954. The final Project 4.1 report began in its preface with the statement that "Operation CASTLE did not include a biomedical program" (it mentions this in discussing the ad hoc nature by which the project personnel were assembled). All official and mainstream historical accounts of the "Bravo" test indicate that its high level of fallout was a result of a miscalculation in relation to its design and was not deliberate (see the Castle Bravo article for more information on the alleged accident).
Castleshaw Roman Fort
Under the supervision of the University of Manchester, further excavation was undertaken on the site in 1957–61 and 1963–64. Between 1984 and 1988, Greater Manchester Archaeological Unit undertook excavations and restoration of the site. A group led by Professor Barri Jones – an expert on Roman Britain – was set up to co-ordinate the work. North West Water, then the owners of the site, ensured the area would not be used for agriculture. In an attempt to make the site accessible to the public, the outline of the fort and fortlet was marked out in low mounds and an education centre was set up nearby. The area beyond the fort was investigated for the first time in 1995–96; archaeologists were searching for a civilian settlement or "vicus" associated with the fort. Surveys revealed a settlement triangular in shape and to the south of the fort. The "vicus" is listed as a Scheduled Ancient Monument with the fort and fortlet.