Where Japan Chooses to Kick Back

History marks Nagasaki as one of only two places to have been devastated by an atom bomb. But four centuries before that epochal event, Nagasaki was known for something much sunnier than a dark mushroom cloud. Over a 200-year period during which Japan quarantined itself from the outside world-no explorers, no traders and above all no missionaries-Nagasaki was the one place foreigners were allowed to live. Dutch and Chinese traders, tolerated because they were not Catholic, called upon the city, leaving behind architecture, food and traditions that have been absorbed into Nagasaki's culture.

Today, Nagasaki offers a respite for travelers exhausted by...