Bala Lake Railway runs a narrow-gauge steam service along the southern shore of Llyn Tegid, using part of the old Ruabon to Barmouth route. The ride is gentle rather than dramatic, but the lake and mountain views make it one of Bala's classic family-friendly outings.
Check the timetable before turning up, especially outside summer. The line is planning a town extension, but services currently start at Llanuwchllyn.