Meitetsuin is also known as "Hydrangea Temple" and is overwhelmed by the beauty of hydrangeas blooming on both sides of the approaching stone steps leading to the mountain gate. Hydrangea's color is blue in color, its name is also called "Meitetsuin Blue". About 2,500 shares are said to bloom all together at the same time. The time of the best time to see hydrangea is roughly from mid June to late June. There is a circular window in the main hall, which expresses enlightenment, truth, and the universe in a circle. It is also known as "Window of Enlightenment" and the scenery of the background garden coloring in the four seasons is cut off and it looks like a beautiful picture.