Eighty percent of the museum's structure is beneath the earth so as to preserve its natural environment and to assimilate it into the surrounding scenery. This unique design clearly demonstrates the intention of its designer, I. M. Pei, to create a paradise on earth. When he first visited the site, he was moved to declare, "This is Shangri-La."

The Subterranean Structure: an integration of man-made form and nature
  Far from crowded cities, the Miho Museum is nestled among the verdant Shigaraki Mountains. The path to the museum angles toward its entrance through a tunnel and over a bridge that spans two mountain ridges. When approaching, one can see tantalizing glimpses of the glass roofs above the pine-filled mountain slope. As with the earthly paradise in the old Chinese tale, "Peach Blossom Spring", most of the museum is hidden.

The Interior: an experience of luminous, open space
  Once inside, one perceives a dramatic change from that of the museum's exterior. Sunlight softly pours through the louvered space-frames of the roof into a spacious reception area and illuminates the honey-colored limestone walls, giving them a warm glow. The sense of breadth and distance is further extended by panoramic views of the distant mountains that surround the building.
  "I am certain that those who come here will understand that I consciously designed the museum to be assimilated into nature." As this remark by Mr. Pei suggests, the museum is a magnificent embodiment of two aspects of architecture: a structure standing in nature and at the same time being a part of nature.