Okunoin Cemetery is a sacred Buddhist site and cemetery located on Mount Koya in Japan. It was opened in 835 and houses the mausoleum of Kūkai, the founder of the Shingon school of Buddhism. With over 200,000 graves and memorial monuments, it's considered the largest cemetery in Japan. Visitors can walk along a 2-kilometer-long cobblestone path lined with tall conifers to reach Kūkai's mausoleum, where thousands of lanterns are lit in perpetuity. The cemetery is a place of pilgrimage, where monks bring ritual offerings to honor Kūkai, who is believed to be in eternal meditation.