Fukuoka

Fukuoka's advantage is geometry. Its airport is two subway stops from the main downtown station — about ten minutes, which is close to unique among cities this size — and it sits at the end of the Kyushu shinkansen line. That makes it the obvious one-way finish for a long route: travel west from Tokyo, work down through the island, and fly home from the south instead of spending two days retracing the corridor.

The city itself is low on landmarks and high on eating. The yatai are the distinctive part: open-sided food stalls that appear along the Naka river and around Tenjin in the evening, seating a dozen people each, serving ramen, grilled skewers and beer until late. Tonkotsu ramen originates here, and the standard counter version costs well under ¥1,000 with a refill of noodles thrown in for change.

Inland is where the days go. Mount Aso's caldera and its volcanic grassland are a couple of hours away, and the onsen towns of Beppu and Yufuin are on the other coast — all reachable by rail or bus, all cheaper to sleep in than anywhere on the Tokaido corridor. This is also the part of Japan where a rental car earns its keep, because the bus timetables in the interior are sparse and the crater road closes on volcanic and weather alerts without much notice.