Hashihaka Kofun, also known as Hashinakayama Kofun, is an enormous ancient burial mound located in Hashinaka, Sakurai City, Nara Prefecture. Widely regarded as one of the earliest keyhole-shaped burial mounds in the Japanese archipelago, it is an important archaeological site for understanding the emergence of early Japanese political authority and state formation.
The Imperial Household Agency manages the mound as Oichinōhaka and identifies it as the tomb of Yamato Totohi Momoso-hime, a princess said to have been the daughter of the legendary Emperor Kōrei, Japan’s seventh emperor according to traditional accounts. Another long-standing theory proposes that the mound may be the burial place of Himiko, the queen associated with the ancient polity of Yamatai. The identity of the person buried here remains a subject of continuing scholarly debate.
Hashihaka Kofun stands within the Makimuku archaeological area, which spreads across an alluvial fan near the northwestern foot of Mount Miwa in the southeastern Nara Basin. The surrounding landscape contains several important early burial mounds, including Hokenoyama Kofun and Makimuku Katsuyama Kofun. Together, these sites form part of the wider Yamato-Yanagimoto or Makimuku groups of ancient tombs.
Among the monuments in this area, Hashihaka Kofun stands out for its exceptional scale, design, and location. It is considered a leading tomb of the Makimuku region. Its construction represents a significant departure from the smaller tombs associated with individual local chiefs, suggesting the emergence of a political power capable of organizing labor and resources across a much wider area.
Hashihaka Kofun measures approximately 278 meters in total length. Its rear circular section is about 150 meters in diameter and reaches approximately 30 meters in height. The front section is around 130 meters wide and 16 meters high. The total volume of earth used to construct the mound is estimated at approximately 370,000 cubic meters, indicating the considerable organizational and labor resources available to its builders.
One of the mound’s most distinctive features is its early-style keyhole shape. The front section spreads outward in a broad, fan-like form resembling a traditional Japanese hand fan. This design is characteristic of some of the earliest keyhole-shaped burial mounds and provides important clues about the monument’s place in the development of ancient Japanese funerary architecture.
The date of Hashihaka Kofun’s construction has long been debated. Based on pottery fragments recovered from the surrounding moat and radiocarbon dating, many researchers favor a date between the middle and latter part of the third century. This period is close to the traditionally estimated death of Himiko, around 248, and is one reason the theory identifying Hashihaka Kofun as her tomb has attracted attention.
However, radiocarbon dating involves uncertainties, and the mound’s keyhole-shaped design does not directly correspond to the descriptions found in the Chinese historical account known as the Records of the Three Kingdoms, including its section on the people of Wa. Some researchers therefore favor a date in or after the early fourth century.
Although the precise construction date and the identity of the person buried here remain unresolved, Hashihaka Kofun is widely recognized as a landmark in the emergence of the Kofun period and the development of early political authority in Japan.
The name Hashihaka is associated with a story recorded in the Nihon Shoki, or Chronicles of Japan, concerning Yamato Totohi Momoso-hime. According to the legend, she became the wife of Ōmononushi, the deity associated with Mount Miwa.
One night, she sought to discover the deity’s true appearance. When Ōmononushi realized that his identity had been seen, he is said to have returned to Mount Miwa. Deeply distressed, Momoso-hime reportedly died after injuring herself with chopsticks. The story explains why her burial place came to be called Hashihaka, meaning “Chopsticks Tomb.”
This mythological account connects the monument with the religious beliefs and worldview of ancient Japan. It also illustrates how stories about deities, rulers, and ancestral figures became intertwined with the landscape and burial places of the Nara Basin.
The theory that Hashihaka Kofun may be the tomb of Himiko was proposed in the Taisho period by archaeologist Shinya Kasai. It has continued to attract researchers interested in the location of Yamatai and the political landscape of third-century Japan.
Supporters point to the possibility that the diameter of the mound’s rear section could be related to the description of a burial mound measuring “more than 100 paces” in the Records of the Three Kingdoms. The proposed third-century construction date is another factor supporting the theory.
There are also significant objections. The enormous scale of Hashihaka Kofun and its distinctive keyhole shape do not fit neatly with every interpretation of the historical texts. As a result, the identification of the tomb as Himiko’s burial place remains unproven. The possibility continues to be discussed, but no conclusive evidence has settled the question.
Visitors cannot enter the burial mound itself, but walking around the site offers a sense of its impressive scale. Part of the surrounding moat has been developed as Hashinaka Oike, a reservoir recognized among Japan’s selected 100 notable reservoirs. The water provides attractive views of the mound, with the surrounding scenery changing throughout the seasons.
In 2017, the moat area was designated a National Historic Site, strengthening the site’s protection as a cultural asset. Hashihaka Kofun remains an important monument for understanding ancient Japan, and its preservation helps ensure that future generations can continue to explore this remarkable period of history.
Hashihaka Kofun is a powerful symbol of the culture, craftsmanship, and political authority that developed during the Kofun period. It should not, however, be confused with the Mozu-Furuichi Kofun Group, a separate collection of burial mounds in Osaka Prefecture that was inscribed on the UNESCO World Heritage List in 2019.
The importance of Hashihaka Kofun lies in its own exceptional archaeological value and its place among the earliest monumental tombs in Japan. Its scale and sophisticated design provide evidence of the social organization and emerging power structures that shaped the ancient Nara region.
Hashihaka Kofun is approximately a 10-minute walk from Makimuku Station on the JR Manyo-Mahoroba Line, also known as the Sakurai Line.
Several other ancient tombs and archaeological sites are scattered throughout the surrounding area, making it an excellent destination for travelers interested in early Japanese history. In spring, cherry blossoms add seasonal beauty to the landscape.
Hashihaka Kofun can be combined with visits to Mount Miwa, Omiwa Jinja, and the wider Makimuku archaeological area. Exploring these sites together offers a deeper understanding of the ancient Yamato region, where religious traditions, political authority, and monumental burial practices developed side by side.
Standing near one of Japan’s earliest enormous keyhole-shaped burial mounds provides a powerful connection with the distant past. At Hashihaka Kofun, mythology and archaeology, historical records and scientific investigation, all meet at a site that continues to inspire questions about the origins of ancient Japan.