Pyramids, one of the world's three largest tombs alongside emperor's tombs
Japan's Nintoku Emperor's Tomb, Egypt's pyramids, and China's Mausoleum of the First Qin Emperor are known as the three largest tombs in the world. It is estimated to have been built over a period of about 20 years in the mid-5th century. The keyhole-shaped front-back circular mound, which is a distinctive feature, will leave a lasting impression once seen.