The Umami Kofun Group is an extensive collection of ancient burial mounds spread across the Umami Hills and surrounding areas in southwestern Nara Prefecture. The group extends across Kawai Town and Koryo Town in Kitakatsuragi District, as well as parts of Kashiba City and Yamatotakada City. With more than 250 burial mounds, it is recognized as one of the Three Great Kofun Groups of Yamato, alongside the Saki Shield-Line Kofun Group and the Yamato-Yanagimoto Kofun Group.
The Umami Hills extend approximately 7 kilometers from north to south and 3 kilometers from east to west, with elevations of around 70–80 meters. The burial mounds are believed to have been constructed between the late fourth and sixth centuries, during Japan’s Kofun period. Many researchers associate this extensive burial ground with the powerful ancient Katsuragi clan, which played an important role in the political and social history of the region.
The Umami Kofun Group is generally divided into three areas—Northern, Central, and Southern—based on the distribution of its large keyhole-shaped burial mounds. Each area contains distinctive archaeological sites that reveal different aspects of ancient Japanese society.
Located in Kawai Town, Otsukayama Kofun is a large keyhole-shaped burial mound dating from the middle of the Kofun period. It measures approximately 215 meters in total length. The circular rear section is 118 meters in diameter and 15.8 meters high, while the rectangular front section measures 123 meters in width and reaches a height of approximately 16.89 meters.
The mound was built in three tiers and is believed to have been covered with stones and surrounded by rows of haniwa, traditional clay figures placed around burial mounds. Its burial facility is thought to have been a vertical stone chamber, a common burial method in ancient Japan.
Shimanoyama Kofun, located in Tōin, Kawanishi Town, is an early Kofun-period burial mound measuring approximately 190 meters in length. It is considered one of the older keyhole-shaped mounds within the Umami Kofun Group and provides important evidence of the development of monumental tomb construction in the region.
The Takayamazuka Kofun Group includes several burial mounds, among which No. 1, also known as Nakaryozuka Kofun, is particularly notable. This keyhole-shaped mound measures approximately 68 meters in length, with a circular rear section 45 meters in diameter and 6.5 meters high.
Excavations have uncovered cylindrical haniwa and house-shaped haniwa, offering clues to ancient burial customs and the symbolic objects placed around tombs.
Located in Mitsuyoshi, Koryo Town, Suyama Kofun is an impressive keyhole-shaped burial mound dating from the early Kofun period. It measures approximately 204 meters in length and is designated a Special Historic Site of Japan.
The mound is surrounded by a moat, a characteristic feature of many large ancient Japanese tombs. Its scale and construction make it one of the most important archaeological sites in the Umami Hills.
Nagareyama Kofun, located in Samita, Kawai Town, was constructed in the first half of the fifth century. The mound measures approximately 105 meters in length.
Part of the mound has been reconstructed to show its original appearance, including the stone covering known as fukiishi and rows of haniwa. These reconstructions help visitors visualize how the burial mound may have looked when it was first built.
Samita Takarazuka Kofun is known for the discovery of more than 30 bronze mirrors, including the remarkable House-Pattern Mirror, or Kaoku-monkyō. The mirror depicts several types of buildings and is an important source of information about ancient Japanese architecture, social organization, and the residences of powerful local rulers.
Located in Otsuka, Koryo Town, Niiyama Kofun is an early Kofun-period burial mound measuring approximately 137 meters in length. Unlike the more familiar keyhole-shaped mounds, it has a rectangular front and rectangular rear section, a form known as a keyhole-shaped square burial mound in Japanese archaeological terminology (zenpō-kōhō-fun).
Excavations uncovered 34 bronze mirrors, making the site particularly significant for research into ancient burial practices and the political relationships of the period.
Kitsui Shiroyama Kofun is located in Kitsui, Kashiba City, and dates from the later Kofun period. This keyhole-shaped mound measures approximately 109 meters in length.
A surrounding moat and rows of cylindrical haniwa are among its notable features. These elements reflect the elaborate construction techniques and ceremonial traditions associated with ancient elite burials.
Located in Tsukiyama, Yamatotakada City, Tsukiyama Kofun is a large keyhole-shaped mound dating from the middle Kofun period. It measures approximately 210 meters in length.
The site is classified as an imperial mausoleum reference site, a designation indicating that it is regarded as a possible location associated with an imperial burial. Its impressive size reflects the status of the person or family for whom it was constructed.
The Umami Kofun Group developed during the early and middle Kofun periods, when powerful clans across Japan built monumental burial mounds to demonstrate their authority and social standing.
The Katsuragi region is thought to have been an important center of power during this era. The size and shape of its burial mounds, together with the discovery of bronze mirrors, haniwa, and other grave goods, provide valuable evidence of the region’s political relationships, social hierarchy, and cultural development.
These sites also help researchers understand how ancient communities organized labor, expressed religious beliefs, and maintained connections with other parts of Japan and the wider East Asian world.
The Umami Kofun Group can be explored from the surrounding towns, with Kintetsu Osaka Line stations such as Goido and Yamatotakada providing useful access points to the region.
Much of the surrounding landscape has been developed as Umami Hills Park, a spacious green area suitable for walking, relaxing, and picnicking. Visitors can combine time outdoors with an exploration of the area’s archaeological heritage, enjoying the natural scenery while discovering traces of ancient Japan.
The Umami Kofun Group is an essential destination for travelers interested in Japanese archaeology and early history. Its hundreds of burial mounds, impressive monumental structures, and remarkable discoveries offer a glimpse into a period when powerful clans shaped the political and cultural landscape of Japan.
Exploring the Umami Hills provides a memorable opportunity to experience the scale of ancient Japanese burial traditions and appreciate the historical legacy preserved in the countryside of Nara Prefecture.