Nagasaki is a city full of history, and strolling around the city streets gives you a glimpse into that. Whether it's visiting the Nagasaki Peace Park, Dejima, Chinatown or one of the area's many churches, you can learn a great deal about what has made Nagasaki into the city it is today.
If all that strolling begins to take its toll on you (the city is hilly, after all!), a great way of getting around is via the network of trams that traverse the streets. The trams are inexpensive and convenient, usually located in close proximity to major points of interest.
Nagasaki is easily accessible via multiple airlines directly from Tokyo. The flight time is around 1 hour and 50 minutes.
Alternatively, if you're traveling by train, the Nozomi Shinkansen will get you to Hakata Station in Fukuoka Prefecture. From there, the Limited Express Kamome train continues on to Nagasaki Station. Total train transit time is approximately 7 hours.