While Early and Middle Kofun burial mounds were mostly stone-lined chambers placed into the top of the mounds, and usually entered from the top, the Late Kofun chambers were set on the ground under or in the barrow mound (see the Chibusan Kofun) and entered from the side through a tunnel-like passageway called yokoana chambers (lit. “horizontal” or “sideways” -“hole”).
Some of these yokoana chambers were set in the mound, while others were cut into hillsides or set into rockcaves or catacombs, like the Yoshimi Yokoana Kofun 吉見百穴pictured at the top of this page or the Ichigao Yokoana Kofun immediately below.
The majority of the Late Kofun (mainly apparently pre-Buddhist) rock-cut tunnel tombs of the 6th and 7th centuries were either simply cut into the soft hillside rock, as in Kumamoto, or dug into the hard loam, as on the Kantō Plain.
Their interiors tend to be, for the most part, austere and simple, probably in keeping with the warrior sensibilities of the interred, especially those of the Kanto Musashino region.
However, there are a few yokoana that possess modest but still enigmatic and intriguing carvings around the entrances or painting or wall incisions in their interiors, such as those of the Chibusan and Nabeta Yokoana Kofun pictured below.
These, are reminiscent of those splendid decorated tumuli that have captured the public’s imagination.
Above: Murals found in the Kitora Kofun
Both these tombs are thought to date to the very end of the 7th century, and its murals are considered to be the finest examples of the some 300 decorated horizontal tomb murals, along with the ‘Ōzuka’ (the King’s grave) Kofun in Kyushu which is however, a keyhole tumulus.
Below are details and descriptions of several yokoana tomb clusters:
The 19 graves are located in the hills where the Tsurumi River begins. These yokoana can be grouped into several types by their interior design.
In 1933 and in 1956, things such as arms, accessories and pottery were discovered in the yokoana. From the context of the many other ruins discovered around Ichigao and Eda, it is thought that the area was a center of the ancient Tsuzuki country. See this page for access information. Below are diagrams showing interment burial position and grave goods found in among the catacombs.
— In Kumamoto Prefecture, is the Ōmura yokoana-gun or Omura Cave Tomb Cluster 大村横穴群 (Hitoyoshi city)
At the 24 Ōmura (or Jōhon) yokoana tombs on the outskirts of Hitoyoshi city, a flat carving of five horses and three bells is visible in tombs 7 and 8. One horse is saddled and another resembles a foal. Zigzags, perhaps representing a gable, mark the lintel over Tomb 8, with a triangle and quiver to one side. Quivers are often proportionately larger than surrounding imagery, probably symbolizing status.
— Also in Kumamoto Prefecture, are the Nabeta yokoana tombs:
Along the face of the cliff, are lined 54 tunnel tombs, the entrance of the largest of which, contains a sunken relief about 2.5 m wide. The roughly hewn outlines depict a warrior and his weapons, a man holding a bow backwards, with a tomo (wrist guard), a large and a small quiver, a knife and shield; underneath, in the centre, is a quadruped, presumably a horse.
— In Miyagi Prefecture, are Oido Yokoana History Park of Wakuya Town:
There are several hundred “yokoana” carved into the southern side of Nonodake Hill from Oido to Nakano. These are the ruins of tombs built from the late 7th to the early 8th centuries. The site is designated as a historic site by the municipal government. The area including 9 of the caves is arranged into Oido Yokoana History Park and open to the public.
The largest tomb is 9 meters in total length. A house-shaped chamber, with three platforms to place coffins on is found at the end of the tomb. The walls of another cave are decorated with chisel carvings and painted red with bengara (iron rust). Pieces of beads made of glass, jade, agate and amber have been excavated, from which it is inferred that those are the tombs of a local ruling family.
— In Fukushima Prefecture, the Izumizaki Cave Tumulus or Yokoana Kofun 泉崎横穴, is cut into the tuff cliff in Izumizaki village.
It is an ornamental tumulus of the Late Kofun Age (early 7th century). On the ceiling and the walls of the coffin-room (depth: 2.2m, width: 2m, height: 1.2m), are depictions of men, animals, horses and eddy patterns, painted in single red color. The tumulus was found and excavated in 1933 as the first found ornamental tumulus in Tohoku area of Japan (p. 17 of Case Studies in the Conservation of Wall Paintings)
The tomb culture and images above are similar and appear related to those of the Kiyotosaku 清戸迫横穴 76 rockcut tomb (pictured below Photo courtesy: Fukushima Prefecture Education Board) also belonging to the Kofun culture dating between 300 AD and 700 AD (exact date unknown).
The yokoana with its mural art and solar and pastoral motifs, displayed at the Futaba-Machi’s History and Folklore Museum, a couple of hours north of Tokyo via the coastal railway line between Iwaki and Sendai. (The above yokoana’s location is near the Fukushima Daiichi nuclear zone.)
— Also in Fukushima Prefecture, is another yokoana with striking murals, the Nakada Yokoana Kofun 中田横穴 in Iwaki City
What are the origins of this rockcut tomb technology?
Their origins are shrouded in mystery. We can, however, consider a few things about the catacomb culture elsewhere:
The earliest rockcut grottoes in Central Asia appeared between 357 A.D. and 384 the caves of Loulan, the caves of Kirzil, the caves of Longmen (near Loyang), those of Yun Kang and the famous Dun-huang in West Gansu (Issner, Ivar Silent Past – Mysterious and Forgotten Cultures of the World, see p. 224). These rockcut caves bore mostly Buddhist cultural artefacts, that, however, did not resemble those found in the Japanese catacombs, despite the fact that Buddhism was filtering into the islands around this time. Instead, the Yokoana catacombs of Japan appear closest to those of the Transcaucasian Bronze Age culture called the Kura-Araxes culture (of the Ancient Near East and West Eurasian steppes – see map below) or the catacomb culture thought to belong to the tribes of the North Caucasus or the descendants of the Proto-Indo-Iranians who are thought to have expanded from the Proto-Indo-European homeland north of the Caspian sea south to the Caucasus, Central Asia, the Iranian plateau, and Northern India.
We are told in The Genesis of North Caucasus Culture … that:
“The cave construction technique has not changed considerably for dozens of millennia. This knowhow reached the greatest perfection in the Caucasus and the Crimea due to their relief and climate.
Since times immemorial, caves were used as sanctuaries, especially connected with the underworld cults. Priests and wizards hearkened to the voice of earth as they performed cave rites. The magic power of the earth’s entrails was believed to penetrate and invigorate them. Indicatively, caves and grottos were ordinary seats of the oracles. As he struggled into the earth’s depths, man was overawed—hence the cults of caves and subterranean demons. Thus, the rock and cave structures of Urartu had their protector deity, Airiani.
Caves also served as burial grounds—antecedents of the later catacombs and vaults. This burial culture developed for several thousand years in the oldest areas of Nakh tribal settlement in Chechnya and throughout the Caucasus. For instance, cave burial grounds have been found in many places of the Chechen highlands—in particular, in the vicinity of the Guchan-Kale, Tuskharoi and Bamut villages, while vaults built into rock niches are frequently met in the principal necropolises. … Stone vaults are undersize replicas of dwellings. Dolmens, which preceded them in the Caucasus and were of almost the same shape, were made of cyclopean stone slabs at the time when man began to build dwellings of huge stones.
These parallels between the abodes of the living and the dead are observed in many nations and millennia.”
Thus the Kofun culture may have been derived from one or several of the migrating nomadic-warrior lineages from the Caucasian region, interacting with the East Asian and Hunnic/Xiongnu-Mongolic tribes as they made their way from the Caucasus through Mongolia or North China and down the Korean peninsula and/or with Indo-Iranian migrants via alternative southern Silk Routes through Southeast Asia.
Since it is in fact, only in the Ukraine and the North Caucasus that we find the probable provenance of the architecture of the gable roof AND chigi and katsuogi forked finial features that form the familiar and distinctive look of Japanese shrines such as seen in Ise Jingu, and that go back even earlier to the form of the clay haniwa houses of the Kofun Period… we may surmise an early connection there. The technology and culture for the dolmens, the V forked shrine roof finials and cyclopean barrow stoneworks and mirrors (early Sarmatian mirrors), not to mention, horse and chariot implements, ostensibly all stem and derive from this region.
Extreme left shows a Cucuteni Tripolye hut model with pole finials for the roof, the middle picture shows a Cucuteni terracotta funerary model of residences, while the far right-hand picture is of the distinctive chigi and katsuogi roof of Naiku Shrine, Ise Jingu.
Source readings and references:
追戸横穴墓群 Oido-yokoana-bo-gun Oido Yokoana Tombs (NIPPON-KICHI website)
Chibusan and Obusan Yokoana Kofun, Japan Geographic
Ozuka Kofun, Kyushu (The Megalithic Portal)
Kofun period by Charles T. Keally
Mural paintings of the Kitora burial mound ;Tiger-man image found in tomb (Yomiuri Shimbun, Jan 23, 2002); Stone chamber of Kitora mound on display for one time only (AWSJ, Jun 2013)
Stone chamber of the Kitora Mound
Lecture abstracts (by the Institute for the Conservation and Restoration of Cultural Properties, Kansai University) of the Nov 13, 2010 International Meeting on Case Studies in the Conservation of Wall Paintings
Izumizaki Historical Museum website
Masafumi, Ito 北陸における横穴墓の諸問題
Kanazuka, Yoshikazu Yoshimi hyakketsu yokoana bogun no kenkyū, Tōkyō Azekura Shobō 1975
Yoshimi Yokoana Kofun (Youtubev video clip)
Kohl, Philip L. Situating the Kura-Araxes Early Transcaucasian ‘Culture’ within the History of Bronze Age Eurasia Tel Aviv vol. 36, 2009 241–265
R i m a n i s h v i l i, Go d e r d z i na The Genesis of North Caucasian Material Culture and Chechen Ethnogeny