Okunoin Cemetery, an epic and truly top 10 place to visit in Japan, is a sacred Buddhist site located on Mount Koya and serves as the final resting place of Kūkai, the founder of the Shingon school of Buddhism. Maybe the place where we, strangely, felt happiest. It's considered the largest cemetery in Japan, with over 200,000 graves and memorial monuments, including those of many famous people, and offers perhaps the most tranquil walk you can take in all of Japan. Visitors can stroll along a 2-kilometer-long cobblestone path lined with towering conifers to reach Kūkai's mausoleum, and remarkably, despite its historical significance, it remains uncrowded and free to visit. The site is steeped in history and spirituality, making it a popular destination for pilgrims and tourists alike.