This museum is an almost certain destination for those visiting Nagasaki for the first time. It almost seems inconceivable that someone could have been to Nagasaki and not have visited this historic, educational, and ultimately heart-breaking place. It is obviously devoted to Nagasaki's atomic holocaust, but there are displays on modern nuclear technology and concerns as well. Seeing the 900 or so artifacts will require some time, and you may certainly want to spend some considerable extra minutes in the video room or at the other video displays. Admission is JPY200 for adults (JPY100 for students), and parking is available.

On 9 August 1945, Nagasaki was the target of the world's second atomic bomb attack at 11:02 a.m., when the north of the city was destroyed and an estimated 40,000 people were killed. According to statistics given at the Nagasaki Peace Park, the dead totaled 73,884, injured 74,909 and diseased 120,820. Most of those who died were civilians.

The city was rebuilt after the war, albeit dramatically changed. New temples were built, as well as new churches due to an increase in the presence of Christianity. Nagasaki is the seat of a Catholic archdiocese led by Archbishop Joseph Mitsuaki Tagami. Some of the rubble was left as a memorial, such as a one-legged torii gate and an arch near ground zero. New structures were also raised as memorials, such as the Atomic Bomb Museum. Nagasaki remains first and foremost a port city, supporting a rich shipping industry and setting a strong example of perseverance and peace.

The atomic bombings of Hiroshima and Nagasaki were nuclear attacks during World War II against the Empire of Japan by the United States of America under US President Harry S. Truman. On August 6, 1945, the nuclear weapon "Little Boy" was dropped on the city of Hiroshima, followed on August 9, 1945 by the detonation of the "Fat Man" nuclear bomb over Nagasaki.

In estimating the number of deaths caused by the attacks, there are several factors that make it difficult to arrive at reliable figures: inadequacies in the records given the confusion of the times, the many victims who died months or years after the bombing as a result of radiation exposure, and the pressure to either exaggerate or minimize the numbers, depending upon political agenda. That said, it is estimated that as many as 140,000 had died in Hiroshima by the bomb and its associated effects, with the estimate for Nagasaki roughly 74,000. In both cities, the overwhelming majority of the deaths were those of civilians.

The role of the bombings in Japan's surrender, as well as the effects and justification of them, has been subject to much debate. In the U.S., the prevailing view is that the bombings ended the war months sooner than would otherwise have been the case, saving many lives that would have been lost on both sides if the planned invasion of Japan had taken place. In Japan, the prevailing view is that the bombings were unjustified, and that knowingly inflicting harm of this magnitude on civilians was inherently immoral.

On August 15, 1945 Japan announced its surrender to the Allied Powers, signing the Instrument of Surrender on September 2 which officially ended World War II. Furthermore, the experience of bombing led post-war Japan to adopt Three Non-Nuclear Principles, which forbids Japan from nuclear armament.