" Nuclear weapons tests have been carried out all over the world. In the Pacific at: Bikini Atoll (U.S.); Christmas Island (U.S./U.K.); Eniwetok Atoll (U.S.); Fangataufa Atoll (Fr); Johnston Atoll (U.S.); Malden Island (U.K.) and; Mororua Atoll (Fr). Also, in Australia, Monte Bello Island, at Emu Fields, and Maralinga (U.K. tests).
In the U.S.: Nevada (several sites; but the Nevada Test Site is the only currently open U.S. test site); Alamogordo, New Mexico; Carlsbad, New Mexico; Hattiesberg, Mississippi; Grand Valley, Colorado; Rifle, Colorado; Farmington, New Mexico; Hot Creek Valley, Central Nevada; Fallon, Nevada and; Amchitka, Alaska."
See also here for info on the three nuke blasts set off on Amchitka. (Three!?)