We also visited the Nagasaki Peace Museum, which was similar to the one in Hiroshima but on a smaller scale. I liked the animated reenactment of the bombing, and also the replica of the Fatman bomb that destroyed the area around the Mitsubishi Arms factory north of Nagasaki (but fortunately left most of the city centre intact).
On the way out we passed through massive stone lanterns and remains of World War II air raid shelters.
We returned back to Shianbashi via streetcar No. 1 and had dinner at Dotour in Hamanomachi (two rolls – mine was prawn and avocado).