It is located in a high marshland on the northeastern slope of Mt. Niseko Annupuri (570m above sea level). This marshland is mainly maintained by melting snow, and on the opposite bank of the marsh there is a forest that is close to primeval, with giant trees such as Mizunara oak, Itaya maple, and Magnolia obovata. On windless days, the surrounding scenery is reflected on the water's surface like a mirror, hence the name.

There are two main routes to Kagami-numa. One is the "HANAZONO GOLF Route" which starts near the Hanazono Golf Course in Hanazono 1, Kutchan-cho. The other is the "Route 58 Route" which starts along Route 58 (Hanazono, Kutchan-cho to Goshiki Onsen). Each route has its own characteristics, so choose the route you prefer.
*There is a floating island in the swamp that constantly moves depending on the wind of the day. Try and find it.

The "HANAZONO GOLF Route" starts at a wooden bridge near the golf course. After crossing three bridges and walking through the forest, you'll come to a pleasant open space. There is a boardwalk around Kagami-numa, making it easy to walk, and there are benches where you can take a break.

Route 58 is a few minutes' drive from the winter-closed Hanazono Gate on Prefectural Route 58 (Kutchan-Niseko Line) and you will see the entrance to Kagami-numa on your left. It takes about 35 minutes to walk from the entrance to reach Kagami-numa. The course is a mountain path with ups and downs and points where you have to cross streams.