Lake Shikotsu
Formed approximately 40,000 years ago by volcanic activity, Lake Shikotsu is a caldera lake with a circumference of about 40 kilometers and a maximum depth of 360 meters, making it the second deepest lake in Japan. Its low nutrient content and minimal plankton growth result in exceptional water clarity, earning it a reputation as one of Japan’s clearest lakes. The way the water shimmers a brilliant blue under sunlight is affectionately known as “Shikotsu Blue.”
Lake Shikotsu is absolutely beautiful! The water is so clear and calm, surrounded by mountains—super relaxing. Taking a boat ride or soaking in the hot springs here is fantastic. It's a great place to visit on your day off!