Saiko Lake, also known as Western Lake, is a picturesque spot located near Mount Fuji in Japan. It's part of the Fuji Five Lakes and is the fourth largest in terms of surface area. The lake used to be connected to two other lakes until a volcanic eruption split them apart centuries ago. Saiko is a popular destination for tourists, offering activities like windsurfing, fishing, and boat excursions. Plus, it's home to some unique fish species, like the Kunimasu trout, which was thought to be extinct until it was rediscovered in the lake in 2010. Overall, Saiko Lake is a beautiful and fascinating place to explore in the shadow of Japan's iconic mountain.