Without your own transport, the best way of getting to Unzen is by bus. Six direct services depart from Nagasaki’s Ken-ei bus station (¥1900) every day, or JR pass holders can take the train to Isahaya Station (諫早) and pick up a Nagasaki Ken-ei bus from the other side of the road (¥1300). Unzen has two bus stations: Ken-ei buses from Nagasaki and Isahaya pull in at the far north end of town, while Shimatetsu buses for the onward journey to Shimabara depart from a square a little further back down the main road.
For general information about accommodation and transport, try Unzen Information Centre (daily 9am–5pm; t 0957/73-3434, w http://www.unzen.org), located at the south end of town, next to Unzen Spa House. The post office opposite has an ATM that accepts international cards (Mon–Fri 9am–5.30pm, Sat 9am–12.30pm).