Moat settlement (環濠集落)

A moat settlement is a village surrounded by a moat. The use of moat is thought to have been introduced to Japan from the Chinese continent along with wet-rice cultivation, forming a new style of village boundary.

The word for moat settlement in Japanese may be written in different ways to indicate whether it is a moat filled with water (環濠) or it is a dry moat (環壕).

Origin

Water moat and dry moat are respectively thought to have its origin in the midstream of the Yangtze River and in Inner Mongolia (where the Xinglongwa Culture flourished), and were built in various places on the Japanese archipelago since the Yayoi period until the medieval period.

In the midstream of the Yangtze River, remains of an 8,000 years old moat settlement were discovered at the Pengtoushan site, located on the Li Yang flatlands in Hunan Province. The moat settlement spanned approximately 200 m across, and while the village was directly facing the natural river on the west side, it was apparently surrounded by a moat of about 20 m wide on the north, east and south sides. These remains of wet-rice farming await further excavation for details to be known.

At the Xinglongwa site located in Chifeng City, Inner Mongolia, remains of an approximately 7,400 to 8,200 years old moat settlement were discovered. Here a village occupying a rectangular ground area of 183 m (long-side) by 166 m (short-side) was surrounded by an oval moat. The moat measured about 1.5 to 2 m wide and 1 m deep. About 100 pit dwellings were found inside the moat surrounded area. The inhabitants lived on cultivating crops such as millet.

Originating in China, moat settlement was transmitted to Japan through the Korean Peninsula as one of the important elements of agricultural culture.

Characteristics

The characteristics of moat settlement was twofold: it was a defensive fort and a foothold. The defensive aspect can be seen by the way moats were dug down, steeply to a point at the bottom making it shaped like a "V," being accompanied with abatis called Sakamogi, which are kind of stakes with sharpened tops directed outwards, along its sidelines. Larger settlements were surrounded by neighboring smaller settlements, were used over a longer time with a larger number of population, contained the chief's residence and a large pit facility where rituals were held, produced metal ware in the village, and various materials received from remote regions in trade are excavated from remaining sites. These findings show that larger moat settlements functioned as a central foothold of politics and economy.

As Wakoku was strengthening its position as a kingdom during the mid-Yayoi period, the defensive aspect of moat settlements as well as upland settlements became more evident to reflect the kingdom's military trend. Once Wakoku had advanced its sovereignty by early Kofun (tumulus) period, chiefs began placing their residences outside the village, and moat settlements were gradually dismantled.

Jomon period

Moat settlements of this time can be found in the southern area of Korean Peninsula, as well as in northern Kyushu, which dates to late Jomon period (the fourth century B.C.)
Jomon man village tended not to have any moat. Ruins of a moat settlement, estimated to be 4,000 years old, was found in Shizukawa 16, Tomakomai City, Hokkaido, whose surrounding oval ditch measured about 56 m (major axis) by 40 m (minor axis) large, 2 m deep with a "V" shaped cross section and 1 to 2 m wide. Two round shaped pit dwelling houses were discovered inside the moat surrounded area, while 15 were discovered outside. This moat settlement is thought to have had different functions than that of Yayoi period. For example, it may have been a place where Jomon man held religious services.

This is the only moat settlement site of the Jomon period discovered to date.

Yayoi period

The moat settlement is thought to have introduced to Japan from the Chinese continent along with wet-rice cultivation, spreading eastward on the archipelago. Between the end of the second century and the beginning of the third century, however, this distinctive Yayoi period style of moat settlement started to disappear from many regions. This is believed to be some sign signifying a radical change in the political situation that was happening around this time, not only in western Japan but also in Tokai and Kanto regions.

The oldest moat settlement from the Yayoi period known until now is the one from Initial Yayoi period discovered at Etsuji site of Kasuya-machi, Fukuoka Prefecture, located nearby the coast of Genkainada in northern Kyushu.

In Kinki region, there is a moat settlement from the first half of the Early Yayoi period found at Daikai site in Kobe city, while none is known from the Initial Yayoi period. Surrounded by a moat measuring 70 m (long-side) by 40 m (short-side), several pit dwelling houses and storages were found. The moat had "V" and "U" shaped sections, and is believed to have been 2 m wide and 1.5 m deep. Most stone tools excavated from the site were simpler ones shaped by chipping or flaking.

The moat settlement discovered at Asahi site in Aichi Prefecture is an example from the Middle Yayoi period, and is known for having consisted of some of the most advanced defensive facilities. Here the village was encircled by a large moat fortified with an earthen wall equipped with a fence on top, further surrounded by three external bands of fences with abatis directed outwards.

Pits were excavated on top of the earthen wall which suggests the existence of a fence above the wall.

Individual moat settlements were developed beyond the end of Early Yayoi period in preparation for conflicts between villages over the control of land and water, as wet-rice cultivation became established in various districts on the west side of the Nobi Plain. About the same time, moat settlements appeared in such places as Itatsuki site in Fukuoka City, Ama site in Takatsuki City, Osaka Prefecture, and Ogidani site in Kyotango City, Kyoto Prefecture. The settlement at Itatsuki site had a surrounding "V" shaped moat of at least 2 m wide and deeper than 1 m, forming an oval measuring 120 m (major axis) by 100 m (minor axis). Dwellings and pits were also discovered outside the moat. At Ogidani site, the village was surrounded by a moat measuring 270 m (major axis) by 250 m (minor axis), 6 m wide in its widest section and 4 m deep. The layout discovered at these sites suggests that the moat was for defending the village. Village constructions were probably common by the end of Early Yayoi period in regions such as northern Kyushu and Kinki, where wet-rice cultivation had been established by that time. After Middle Yayoi period and onwards, moat settlements were spread all over Kinki region, and people lived in large villages that had a surrounding moat of 300 m to 400 m in diameter.

Yoshinogari site in Saga Prefecture, Ama and Ikegami-Sone sites in Osaka Prefecture, and Karako-Kagi site in Nara Prefecture are examples of places where large scale moat settlements from Late Yayoi period existed.

Moat settlements of this period were built in lowlands, and usually had an earthen wall on the outer side of the moat (whereas in the Medieval period earthen walls were built on the inner side). It is believed that the purpose of creating a moat to divide the inner and outer space of a village was to protect itself from being attacked by any external enemy or wild life. In some cases there were two or three moats built, forming together a huge moat band zone. The different size of moats were probably representing how strong a chieftaincy's controlling power was over wet-rice cultivation in the area, how tight the community was united, or the difference in villager classes who lived inside and outside the moat. Water moats also functioned as flood control.

Medieval period

The latter half of the Muromachi period was the Sengoku period (period of warring states) when warfare broke out all over Japan, making some villagers decide to build moats around their settlements in order to protect themselves from assaults. Remainders of these medieval moat settlements can still be seen in various places of Japan. Moat settlements which grew in scale with an influential Buddhist temple at its center came to be known as Jinai-cho (literally a town with a temple inside).

Ancient remains

There are a limited number of moat settlements which still retain the original features. The full picture of a large scale moat settlement was revealed from the remains at the Yoshinogari site. The recent discovery of Kyozukabana remains in Hakuta-cho, Yasugi City, a land where legend holds that Izanami no kami was buried, was an event which drew wide public attention.

Initial Yayoi period
The moat settlement at Etsuji site (Kasuya-cho, Fukuoka Prefecture) is an example of latter half of Initial Yayoi period, surrounded by two shallow ditches of about one meter wide. This settlement's style was probably made with the strong influence from that in the southern area of Korean Peninsula.

The double moats found at Naka site (Fukuoka Prefecture) are almost perfect circles with an outside diameter of 150 m.

Early Yayoi period
Moat settlements began to spread eastward from northern part of Kyushu along the coast of Seto Inland Sea, and then to Osaka Bay area. The size of the moat settlement remained small, 70 m to 150 m in diameter, and did not grow bigger than that.

Itatsuki site (Fukuoka City)
Hyakkengawa-Sawada site (Okayama Prefecture)
Nakanoike site (Zentsuji City, Kagawa Prefecture)
Daikai site (Kobe City, Hyogo Prefecture)
Ama site (Takatsuki City, Osaka Prefecture)
Ogidani site (Kyotango City [previously Mineyama-cho], Kyoto Prefecture, Sanin region)

Middle Yayoi period and later
Harunotsuji site (south-east of Iki Island, Nagasaki Prefecture)
Yoshinogari site (Yoshinogari-cho, Saga Prefecture)
Kyozukabana site (Yasugi City, Shimane Prefecture)
Ikegami-Sone site (lies across the border of Izumi City and Izumiotsu City, Osaka Prefecture)
Hieda moat settlement (Yamatokoriyama City, Nara Prefecture)
Karako-Kagi site (Tawaramoto-cho, Nara Prefecture)
Ota-Kuroda site (Wakayama City, Wakayama Prefecture)
Asahi site (lies across the borders of Kiyosu City, Kasuga-cho and Nagoya City, and has one of the most heavily equipped defensive structures)
Otsuka-Saikachido site (Yokohama City, Kanagawa Prefecture)

Extant moat settlements

Hieda moat settlement (Yamatokoriyama City, Nara Prefecture)
Takenouchi moat settlement (Tenri City, Nara Prefecture)
Nango moat settlement (Koryo-cho, Nara Prefecture)
Takayasu moat settlement (Ikaruga-cho, Nara Prefecture)
and others.