Kofun (古墳, from Sino-Japanese "ancient grave") are megalithic tombs or tumuli in Northeast Asia. Kofun were mainly constructed in the Japanese archipelago between the middle of the 3rd century to the early 7th century CE.^[1]

The term is the origin of the name of the Kofun period, which indicates the middle 3rd century to early–middle 6th century. Many kofun have distinctive keyhole-shaped mounds (zempō-kōen fun (前方後円墳)). The Mozu-Furuichi kofungun or tumulus clusters were inscribed on the UNESCO World Heritage List in 2019, while Ishibutai Kofun is one of a number in Asuka-Fujiwara residing on the Tentative List.^[2][3]

Overview

The kofun tumuli have assumed various shapes throughout history. The most common type of kofun is known as a zenpō-kōen-fun (前方後円墳), which is shaped like a keyhole, having one square end and one circular end, when viewed from above. There are also circular-type (empun [ja] (円墳)), "two conjoined rectangles" typed (zenpō-kōhō-fun [ja] (前方後方墳)), and square-type (hōfun [ja] (方墳)) kofun. Orientation of kofun is not specified. For example, in the Saki kofun group, all of the circular parts are facing north, but there is no such formation in the Yanagimoto kofun group. Haniwa, terracotta figures, were arrayed above and in the surroundings to delimit and protect the sacred areas.

Kofun range from several metres to over 400 m long. The largest, which has been attributed to Emperor Nintoku, is Daisen Kofun in Sakai City, Osaka Prefecture.

The funeral chamber was located beneath the round part and comprised a group of megaliths. In 1972, the unlooted Takamatsuzuka Tomb was found in Asuka, and some details of the discovery were revealed. Inside the tightly assembled rocks, white lime plasters were pasted, and colored pictures depict the 'Asuka Beauties' of the court as well as constellations. A stone coffin was placed in the chamber, and accessories, swords, and bronze mirrors were laid both inside and outside the coffin. The wall paintings have been designated national treasures and the grave goods as important cultural property, while the tumulus is a special historic site.^[4][5]

Locations and number

Kofun burial mounds and their remains have been found all over Japan, including remote islands such as Nishinoshima.^[6]

A total of 161,560 kofun tomb sites have been found as of 2001. Hyōgo Prefecture has the most of all prefectures (16,577 sites), and Chiba Prefecture has the second most (13,112 sites).^[7]

History

Yayoi period

Most of the tombs of chiefs in the Yayoi period were square-shaped mounds surrounded by ditches. The most notable example in the late Yayoi period is Tatetsuki Mound Tomb in Kurashiki, Okayama. The mound is about 45 metres wide and 5 metres high and has a shaft chamber. Broken pieces of Tokushu-kidai, cylindrical earthenware, were excavated around the mound.

Another prevalent type of Yayoi period tomb is the Yosumi tosshutsugata funkyūbo, a square mound with protruding corners. These tombs were built in the San'in region, a coastal area off the Sea of Japan. Unearthed articles indicate the existence of alliances between native tribes in the region.

Early Kofun period

One of the first keyhole-shaped kofun was built in the Makimuku area,^[8] the southeastern part of the Nara Basin. Hashihaka Kofun, which was built in the middle of the 3rd century AD, is 280 metres long and 30 metres high. Its scale is obviously different from previous Yayoi tombs. During the next three decades, about 10 kofun were built in the area, which are now called as the Makimuku Kofun Group. A wooden coffin was placed on the bottom of a shaft, and the surrounding walls were built up by flat stones. Finally, megalithic stones formed the roof. Bronze mirrors, iron swords, magatama, clay vessels and other artifacts were found in good condition in undisturbed tombs. Some scholars assume the buried person of Hashihaka kofun was the shadowy ancient Queen Himiko of Yamataikoku, mentioned in the Chinese historical texts. According to the books, Japan was called Wa, which was the confederation of numerous small tribes or countries. The construction of gigantic kofun is the result of the relatively centralized governmental structure in the Nara Basin, possibly the origin of the Yamato polity and the Imperial lineage of Japan.

Mid-Kofun period

During the 5th century AD, the construction of keyhole kofun began in Yamato Province; continued in Kawachi, where gigantic kofun, such as Daisen Kofun of the Emperor Nintoku, were built; and then throughout the country. The proliferation of keyhole kofun is generally assumed to be evidence of the Yamato court's expansion in this age. However, some argue that it simply shows the spread of culture based on progress in distribution, and has little to do with a political breakthrough.

A few tombs from the mid-Baekje era were excavated around the Yeongsan River basin in South Korea.^{[citation needed]} The design of these tombs are notably different. The tombs that were discovered on the Korean peninsula were built between the 5th and 6th centuries CE.^{[citation needed]} There remain questions about who were buried in these tombs such as nobility, aristocracy, warriors or mercenaries.

• Gallery
• 
  An example of keyhole-shaped mound in the Early Kofun period which was drawn in 3DCG.
  (Gosashi Kofun (Nara, Nara), 4th century)
• 
  An example of keyhole-shaped mound in the Mid-Kofun period which was drawn in 3DCG.
  (Nakatsuyama Kofun [ja] (Fujiidera, Osaka), 5th century)
• 
  An example of keyhole-shaped mound in the Late Kofun period which was drawn in 3DCG.
  (Danpusan Kofun (Nagoya), 6th century)

Late Kofun period

Keyhole-shaped kofun disappeared in the late 6th century AD, probably due to the drastic reformation in the Yamato court, where Nihon Shoki records the introduction of Buddhism during this era.

Types

Round Kofun

Round Kofun [ja] are a kind of Kofun^[9]

Square Kofun

Square Kofun [ja] (方墳, hōfun) is a kind of Kofun.^[10] They are not as common as Zenpokoenfun of Keyhole shaped Kofun.^[11]

Scallop Kofun

Scallop Kofun [ja] is a kind of Kofun. It is defined by a circular body with a small part extending. This can make it an interrmediate between a Keyhole-shaped kofun and a circular-type kofun [ja]^[12]

Famous examples include Hokenoyama Kofun in the Makimuku ruins.^{[13][14]: 249} dated to around 250 AD.^[14]: 253 and Nyotaizan Kofun.

Octagonal Kofun

Octagonal Kofun [ja] (八角墳, hakkaku-fun) is a kind of Kofun. They are a very rare kind characteristic of Emperors

Many Japanese Emperors were buried in them including Empress Kōgyoku in Kengoshizuka Kofun.^[15][16], Emperor Tenji in his Mausoleum,^[17] and Emperor Jomei in Dannozuka Kofun^[18][19]

From the end of the 6th century to the beginning of the 7th, the tumuli of the monarchs changed from square hōfun tumuli [ja] to octagonal hakkaku-fun [ja] tumuli.^[20]

List of Octagonal Kofun

• Ise Kofun (Fujioka City) [ja]
• Inari Kofun [ja]
• Oichi No.1 Kofun [ja]
• Kajiyama Kofun
• Kengoshizuka Kofun
• Gobyo Kofun [ja]
• Takei temple ruins
• Dannozuka Kofun
• Tsukamyojin Kofun [ja]
• Nakaoyama Kofun [ja]
• Nakayamasōen Kofun
• King Noguchi Kofun [ja]
• Mitsuya Kofun [ja]
• Yoshida Kofun

Zenpō-kōhō-fun

zenpō-kōhō-fun [ja] (前方後方墳, two conjoined rectangles kofun) is a kind of Kofun. ^[21][22] They are shaped somewhat like the more keyhole shaped Zenpokoenfun, but they have a square body rather than a circular one.^[21][23] They tend to be smaller than Zenpokoenfun.^[24] Yanaida Nunōyama Kofun is one of the largest of the type^[25].

There is a specific style exemplified by Yadani Kofun and Jinyama Tumulus Cluster and Rokuji Kozuka Kofun and Tomisaki Kofungun of Ōzuka-Senbōyama Sites as yosumi-tosshutsugata (四隅突出形), which is square or rectangular, with protrusions on each of its four corners; however, it is unique in that it is not a true rectangle, but has a narrow waist, similar to a "two conjoined rectangles" type (zenpō-kōhō-fun [ja] (前方後方墳)). The slope of the mound is covered with fukiishi -like stones, with a row of larger stones marking its edge, and is surrounded by a two-meter wide moat. The yosumi-tosshutsugata style is unique to the late middle Yayoi period and is most prevalent in western Japan in areas influenced by the Izumo culture. ^[25]

Joenkahofun

Joenkahofun [ja] (上円下方墳) is a kind of Kofun..^[26][27][28] Such kofun have a round dome top with a square bottom.^[27][26][29] This is a quite rare type of Kofun in Japan.^[26]

They are associated with the Asuka Period,^[27][28]

Musashi Fuchū Kumano Jinja Kofun in Fuchū in Tokyo,^[29] and Miyazuka Kofun are two notable examples.^[29]

List of Joenkahofun

• Ishino Karato Kofun [ja]
• Sanno-zuka Ancient Tomb [ja]
• Shimizu Yanagikita No. 1 Tomb [ja]
• Tenmondai Kounai Kofun [ja]
• Nochi Kubo Ancient Tomb [ja]
• Miyazuka Kofun
• Musashi Fuchū Kumano Jinja Kofun

Corridor-type kofun

corridor-type kofun [ja] (横穴式石室, yokoana-shiki sekishitsu) are a kind of Kofun dug as artificial caves in Ancient Japan.^[30][31][32]

Zenpokoenfun

Zenpokoenfun are a notable type of Japanese ancient tombs (Kofun), which consists of a square front part (前方部) and a circular back part (後円部).^[33] The part connecting the two is called the middle part (くびれ部), which looks like a keyhole when viewed from above.^[34]

UNESCO Kofun Group

This list includes the "Mozu-Furuichi Kofun Group: Mounded Tombs of Ancient Japan",^[35] which was inscribed as a UNESCO World Heritage Site on 6 July 2019.^[36]

Aerial photos

• 
  Oyamato, Yanagimoto and Makimuku Kofun Group, Nara Prefecture, 3rd century
• 
  Saki Tatanami Kofun Group and the Heijō-kyō site, Nara Prefecture, 4th century
• 
  Furuichi Kofun Group, Osaka Prefecture, 5th century