Iwate Ryūsendō 岩手龍泉洞 – 日本三大鐘乳洞之一
Ryusendo Cave is an extensive limestone cave in the mountains of Iwaizumi Town in Iwate Prefecture and regarded as one of Japan’s three great limestone caves. It is estimated that the caverns extend nearly 5000 meters into the mountainside, about 3500 meters of which have been explored to date since surveys began in the 1920s. Large volumes of clear, blue water gush forth from the cave’s depths, forming an underground river and four underground lakes in the caverns.
龍泉洞是日本最大的石灰岩洞之一。龍泉洞的主要特色是一連串碧藍色和翡翠綠的地下湖。