Kofun: The Mysterious Giant Tombs of Ancient Japan
In Japan, some green hills conceal a secret dating back more than 1,500 years. They are not natural landforms, but enormous burial mounds built to house the powerful rulers of ancient Japan: the kofun (古墳).
Built mainly between the 3rd and 7th centuries, these monuments bear witness to the emergence of a society organized around powerful ruling families. Some of them reach astonishing dimensions. The most famous, the Daisen Kofun in Sakai, near Osaka, measures approximately 486 meters in length and is traditionally attributed to Emperor Nintoku.
In 2019, the Mozu and Furuichi burial mound groups were inscribed on the UNESCO World Heritage List. This international recognition highlights their exceptional importance as witnesses to Japanese history.
But what do these gigantic hills actually conceal? And why are some of them shaped like enormous keyholes?
1. Kofun: Tombs with Remarkable Shapes
The word kofun means “ancient tomb.” It refers to earthen burial mounds, sometimes surrounded by moats and covered with stones.
Several shapes exist: circular, square and keyhole-shaped. The latter is particularly characteristic of Japan. It combines a rounded rear section with a rectangular front section.
The size of these monuments generally reflected the status of the deceased. The largest were reserved for the most powerful rulers.
Their construction accompanied the rise of Yamato, one of the archipelago’s major political powers at the time. Kofun are therefore much more than burial sites: they bear witness to the organization and influence of the elites of ancient Japan.
2. How Were These Giant Monuments Built?
Building a kofun required considerable organization. Builders had to mark out the site, move enormous quantities of earth, create the surrounding moats and prepare the burial chamber.
The slopes of some burial mounds were covered with rounded stones known as fukiishi. Terracotta figurines were also placed on different parts of the monument.
The Daisen Kofun gives us an idea of the scale of these construction projects. According to an estimate by the city of Sakai, its construction would have required approximately 15 years and 8 months of work, with as many as 2,000 people working each day under the scenario considered.
These figures illustrate the human and technical resources that rulers could mobilize to honor their dead.
3. Haniwa: The Mysterious Terracotta Figurines
It is impossible to talk about kofun without mentioning haniwa (埴輪). These terracotta objects were placed on burial mounds and around the tombs.
The earliest forms were often simple cylinders. Over time, artisans created representations of houses, horses, birds, warriors and human figures.
These figurines were not simply used to decorate the monuments. They played a role in funerary practices and in the symbolic presentation of the tomb.
Today, they are valuable sources of information for archaeologists. The clothing, hairstyles, armor and equipment they depict help us better understand the society of that period.
Their production also demonstrates genuine craftsmanship: artisans worked the clay, shaped the pieces and then fired them before placing them on the burial mounds.
4. Himiko and Nintoku: The Mysterious Figures of the Kofun Period
The history of kofun is associated with several famous figures from ancient Japan.
One of them is Himiko, a queen of the land of Wa mentioned in Chinese chronicles from the 3rd century. Her political and religious role remains fascinating. Some researchers have suggested that her tomb may be associated with the Hashihaka Kofun in Nara Prefecture. However, this theory remains debated and has not been confirmed.
Another name frequently appears: Emperor Nintoku, to whom tradition attributes the gigantic Daisen Kofun in Sakai. Here again, it is important to distinguish traditional attribution from a formally established archaeological identification.
These uncertainties add to the mystery of the kofun: despite ongoing research, the identities of some of the people buried within them remain unknown.
5. Kofun Today: Discovering Japan’s Heritage Near Osaka
The Mozu and Furuichi burial mound groups, located in Osaka Prefecture, include 49 kofun that have been listed as UNESCO World Heritage Sites since July 2019.
In Sakai, the Daisen Kofun impresses visitors with its size and distinctive shape. Although its interior is not open to visitors, it is possible to explore the surrounding area and learn more about its history through the city’s cultural institutions.
The Sakai City Museum and the Mozu Kofun Visitor Center offer opportunities to discover archaeological objects and learn about the history of these monuments. The observation deck at Sakai City Hall also provides an interesting viewpoint overlooking the site.
Visitors can therefore discover these ancient tombs in their present-day surroundings, in the middle of a modern urban area.
The Silent Witnesses of Ancient Japan
Kofun are much more than gigantic tombs. They tell the story of the emergence of political power in Japan, the skills of ancient builders and the work of artisans who created haniwa and funerary objects.
Even today, these mysterious hills recall an era more than fifteen centuries ago. They offer a remarkable contrast between contemporary Japan and its ancient past.
During a trip to Osaka or the Nara region, taking the time to discover a kofun means encountering an exceptional heritage site… and a fascinating chapter in Japanese history.
