Saitobaru: A Walk in Miyazaki’s “Valley of the Kings”

Sitting on a plateau above the Hitotsuse River valley in central Miyazaki Prefecture is a 58 hectare site covered in tumuli, the kofun burial mounds of the period from the second century to the seventh century AD, a period in Japanese history known as the “Kofun Period” because of this practice.  There are at least 319 tombs of various sizes and centuries (ranging from the fourth to the seventh) on this site, including two that are associated with members of the Imperial family.  This makes it one of the largest such burial sites in Kyushu (there are several kofun sites across the island, and some 165,000 known kofun across the entire country, including the ones near the Tama River that I wrote about earlier). Designated as a “special historical site” (the only kofun collection in Kyushu to hold this designation), it is an amazing place to go for a stroll.

Apparently the reason this site was chosen by the ancients was because the kofun on the plateau would be visible to the people living in the valley below.  They would look up and see these structures, sort of halfway between heaven and earth, that marked the final resting place of the most important people in their society.

Thirty Saitobaru kofun were excavated, and their contents studied, just over a century ago, at the beginning of the 20th century, a time when the field of archaeology was nascent in Japan.  In some cases, the contents were removed and are now housed in the nearby Saitobaru Archaeological Museum of Miyazaki Prefecture, which also has educational displays on archaeology and the lives of Kofun Period people.  Unfortunately, the museum was already closed for the New Year’s holidays when I visited, so I was unable to avail myself of its exhibits.

At the museum, there is also an “Ancient Life Interactive Center”, an educational facility designed for school children, to introduce them to what is known about how people of that period lived and worked.  A thatched hut, designed based on an image left on the back of a mirror excavated from one of the tombs, stands nearby, a further testament to the lifestyle of that ancient time.

One interesting feature of the “park” containing the kofun is that parts of it are under cultivation.  One of the most interesting kofun, No. 206, stands on the edge of a field of broccoli.  Rows of tea bushes flank another group of kofun.

Kofun No. 206, also known as Oni-no-iwaya Kofun, was built at the end of the 6th/beginning of the 7th century.  It is interesting not because of the neighboring broccoli, but because of its distinctive donut shape.  It is a circular mound 7.3 meters high surrounded by a ring-shaped mound.  Archaeologists have concluded that there was a moat around the center mound and another around the outside of the ring-shaped mound–a double moat.  In total, it is 37 meters across and is believed to have been the tomb of the local ruler of this area.


Kofun are fundamentally dolmen that have been covered with earth.  This is easily seen at Oni-no-iwaya Kofun, since the entrance to the tomb was left open after its excavation.  While there is a grate across so entry is not possible, the inside is lit up so that visitors can look inside and gain some understanding of the structure.  Usually a stone or wooden coffin was placed against the wall opposite to the entrance.  In Oni-no-iwaya Kofun, archaeologists found iron nails, leading them to conclude that there had been a wooden coffin; all traces of the wood of the coffin and the body it contained have been erased by time.

There are a number of paths around the site taking visitors past various of the kofun.  Of the 319 kofun, 286 are “circle mounds”, relatively simple round mounds. Some are relatively small, perhaps only a meter or so high (perhaps worn down by time), while others are taller, some more than 3 meters.

The other major style of kofun is the so-called keyhole-shaped tomb.  These tombs tend to be much bigger and more elaborate.  They have a primary round mound and a secondary square mound that isn’t quite as tall.  The two are joined by earth mounded between them and when the entire structure is viewed from the air, it looks like a keyhole.  The best-known such kofun is probably the grave of the Emperor Nintoku (290-399 AD) on the outskirts of Osaka that received UNESCO World Heritage listing in the middle of 2019. There are 31 keyhole-shaped kofun at Saitobaru (although none as elaborate as the Emperor Nintoku’s).

Kofun No. 13, a keyhole tomb, is particularly interesting because it is open (only when the museum is open) and can also be climbed.  (Generally, climbing on the kofun is discouraged as it accelerates their erosion, and is arguably disrespectful.)  No. 13 is also quite large, standing 7.2 meters high at its highest point, and 79.4 meters long. Among the items found when it was excavated was a mirror (a common item found in kofun); jade, jasper and glass accessories, weapons and ceramic jars.  No. 13 was covered in river rocks after it was built and those rocks still protect it, although a layer of dirt/grass sits on top of the rocks to protect them.  A 1:20 scale model shows its original appearance.

There is one other display in the park showing what a stone-covered kofun must have looked like.


The kofun that were excavated a century ago have signboards offering further information about them, and often also about the archaeologists responsible for the excavation.

I found strolling through the park on a mild, albeit it slightly overcast, winter day, to be both pleasant and informative.  I hope I can visit again sometime when the museum is open to further my education.

The Saitobaru Kofun are about a 45 minute drive north of Miyazaki, or about 1.5 hours by train and bus.

© 2019 and Vicki L. Beyer
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