Osaka, Japan’s third largest city, is a pulsating commercial hub, famous for its food, and the cityscape rivals Tokyo for neon-lit futurism. If you need respite from the urban sprawl seek out Osaka Castle and the surrounding Nishinomaru Garden, a particularly pretty spot during the cherry blossom season.

On 6 August 1945 the world witnessed the terrifying power of nuclear weapons for the first time, unleashed on the unsuspecting Japanese city of Hiroshima. The modern city's sobering Peace Memorial Park commemorates that fateful day, which left more than 140,000 dead.

Fukuoka is the largest city on the southern island of Kyushu, and has long been an important centre for trade due to its proximity to the Asian mainland, closer to Seoul than it is to Tokyo. It’s a friendly, sunny place, and the city was created by a merger of two towns: Fukuoka, the old castle town, and Hakata, the former merchant district.

Busan is South Korea’s second biggest city and one of the world’s busiest container ports, but it’s an easygoing place with a discernibly different character to Seoul. Haeundae beach is a popular summer holiday destination for Koreans, while the pungent Jagalchi market sells every type of fish and sea creature imaginable.

Three days after Hiroshima was flattened by an atomic bomb, Nagasaki suffered the same horrifying fate. The reconstruction of both cities has been quite extraordinary; Nagasaki today is a vibrant, cosmopolitan place, with a fascinating history that goes back a lot further than 1945.

The friendly southern Japanese city of Kagoshima enjoys a balmy climate, and sits just across the bay from the very active Sakurajima volcano, which erupts so regularly that an ‘ash forecast’ is included in local weather reports.