Enewetak Atoll
Two weapons were detonated at the Enewetak Atoll as part of Operation Ivy in 1952. One of them, Ivy King, was the largest pure-fission bomb ever detonated, with a yield of 500 kilotons, and the other, Ivy Mike, was the first hydrogen bomb device (it was too large to be an actual weapon), with a yield of 10.4 Mt.