The 80km Shinetsu trail, the best woodland trail in Japan, runs over the ridges of the Sekida mountains at about 1,000 meters above sea level, forming a boundary between Nagano and Niigata prefectures. It is one of the few long trails in Japan. This area is blessed with a rich ecosystem nurtured by Japanese beech tree forests. Historically, there were 16 passages connecting Nagano with Niigata. The forests are perhaps best known for their beech trees. The tall, well-shaped beech trees form a corridor of nature along the path. The earth-packed trail also makes it easy to walk. Spring (from mid-June to the end of July) and autumn (from mid-September to the end of October) are great seasons to visit the trail. In the spring, the last traces of snow can be seen among new greenery and flowers bursting into bloom. In the fall, hikers can enjoy the brilliant colors of autumn leaves.