Nishiyama Reservoir Loop

The Nishiyama Reservoir Loop circles the Nishiyama Suigen-chi reservoir in the Nishiyama district of central-eastern Nagasaki. The trailhead is reached by bus from Nagasaki Station to the Nishiyama Daini stop (20 minutes), followed by a 10-minute walk to the reservoir parking area; no permit is required, and a small free parking lot serves the site but fills on weekends. The loop covers 5 km with minimal elevation gain, staying close to reservoir level with only a few gentle rises, making it an easy, non-technical outing. The surface is a mix of paved path and packed gravel encircling the water, with wooden boardwalk sections crossing inlet streams; much of the route is shaded by cherry and maple trees planted along the embankment, though open stretches along the dam wall get full sun. Key landmarks include a dam observation point at the reservoir's southern edge, a small shrine along the eastern shore, and picnic areas near the northern inlet, which make a natural turnaround for a shorter 2.5 km out-and-back. No refuge huts exist along the loop, but vending machines and restrooms are located at the main parking area near the trailhead; hikers should carry their own water for the full circuit since there are no other services along the way.