Because this mountain is famous for its unique natural landscape and rich history and culture. Located in Shizuoka Prefecture, Honshu Island, Japan, near Mount Fuji, Xincang Mountain is a popular tourist attraction. The natural landscape of this mountain is very spectacular. There are huge rocks and deep canyons on the top of the mountain, forming a unique mountain view. It is also rich in history and culture. According to legend, the new Cangshan Mountain was the base of the Yamato court in Japan during the Three Kingdoms period in ancient times, so it was called "the first mountain in the Three Kingdoms". Mountaineering routes are also very popular. In a word, the reason why Japan's Xincang Mountain is called "the first mountain in the Three Kingdoms" is because it is famous for its unique natural landscape and rich history and culture.