While free-wheeling Fukuoka has the best nightlife, Nagasaki evokes a vividly old-world port-city charm. Kumamoto's grand ancient castle retains the city's rustic airs, despite streets teeming with traffic, and Kagoshima is meant for relaxing among its blossoms and palm trees.
Fukuoka is home to Japan's most sought-after noodles: Hakata ramen; filament-thin egg noodles in a broth richly flavored with pork-bones. Nagasaki has chanpon, a buttery noodle soup containing everything from octopus and squid to carrots, cabbage, and celery. Kagoshima's kuro-buta tonkatsu, or Black Pig pork cutlet, is breaded and fried and served with special sauce, cabbage, and pickles made from the world's largest white radishes.
Mt. Aso, in the center of the island, is notoriously active, as is Sakura-jima, a fire-spewing dragon growling and spitting ash across the bay from Kagoshima. Hot springs are found throughout Kyushu, and in the Satsuma Peninsula you can be buried in a berm of hot sand while the magma churns not far below.
With its lava flows, outlying islands, rugged mountain landscapes, thickly forested interior, and gigantic national parks, Kyushu is an adventurer's dream. Many peaks are accessible, the views are incredible, and except for time, most trails don't require more than a good pair of shoes and a jug of water.
A very sleek high-speed train links Kumamoto with Kagoshima within an hour, and from there, in another hour, you can be on or under the hot sand, basking in sunshine down at the palm-lined, wave-lapped, breezy beaches of Ibusuki.