The discovery was made in 1935, when the Buddha Shakyamuni statue from this photo was restored: inside there are internal organs, some of them made of silver, others made from cloth. And this isn't the only statue with internal organs in Japan: in 2012, another one was discovered at a nearby temple, Kofuku-ji...
EXIF info:
Nikon Df
Lens: 24-70mm F/2.8G
Focal Length: 24mm
Aperture: F/3.5
Shutter Speed: 1/60s
ISO Sensitivity: ISO 4000