Rock shelter ruins - Iwakageiseki

This is one of the ancient ruins where a small depression just below a steep cliff was used as a natural dwelling. The large and small depressions created in the rock walls by natural erosion became rock shelters and caves, which were actively used by ancient people as places to live and shelter from the rain and dew. Generally, rock shelter ruins are relatively shallow, with a gentle slope and close to the rock surface, while larger and deeper ruins are called cave ruins because the rock shelter is clearly visible. This classification is purely relative and expedient, but both have the advantage of being cooler in summer and warmer in winter than open land ruins, with less temperature change, making them very comfortable places to live, but at the same time they have the disadvantage of being humid. However, many of them are selected because the north side is covered by a rock wall to protect against the north wind, and the south side has an open view where you can enjoy the sun. These ruins not only contain pottery and stone tools as living tools, but sometimes even shell mounds. Human bones have also been discovered on rare occasions. Not only did they function as living sites, but they were also used as cemeteries. In exceptional cases, ritual remains have been excavated. Because the living space was limited, records of life were recorded multiple times in the same place, and they were deposited intermittently as cultural layers, which is useful for archaeological chronological research. They are found in the Paleolithic, Jomon, Yayoi, and Kofun periods, and some sites overlap. They are found not only in Japan but also in Europe, Asia, and Africa, where there are rock walls and certain conditions are met. Representative examples include the Kamikuroiwa Rock Shelter Site in Kumakogen Town, Kamiukena County, Ehime Prefecture, and the Shimomotoyama Rock Shelter Site in Shimomotoyama Town, Sasebo City, Nagasaki Prefecture.

[Yu Aso]

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

まっすぐに切り立った断崖(だんがい)直下のわずかな広さのくぼみを、天然の住居として利用した古代遺跡の一つ。自然の侵食作用によって岩壁につくられた大小のくぼみは、岩陰や洞窟(どうくつ)となり古代人によって雨露をしのぐ生活の場として積極的に利用された。一般的に、比較的浅い外形をもち、なだらかな傾斜で岩肌が迫るものを岩陰遺跡とよび、規模が大きく奥行が深いものは、岩びさしが明瞭(めいりょう)となるため洞窟遺跡とよんでいる。この類別はあくまでも相対的かつ便宜的なものであるが、両者は開地遺跡に比べて、夏は涼しく冬は温かく温度変化の少ない利点があるため、非常に住み心地がよい場所であったが、同時に湿気をもつ欠点もあった。しかし、多くは北側が岩壁で覆われ北風を防ぎ、南側は眺望の開けた太陽の満喫できる場所を選定する。その遺跡は、生活用具としての土器、石器のみならず、ときには貝塚さえ残している。またまれには人骨の発見もある。生活址(し)としての役割のみならず、墓地としても使われた。特例として祭祀(さいし)遺物を出土する場合もある。生活空間が限定されているため、同じ場所に何回もの生活記録をとどめ、文化層として断続的に堆積(たいせき)し、考古学上の編年研究に役だっている。旧石器、縄文、弥生(やよい)、古墳時代にみられ、重複した遺跡もある。日本のみならずヨーロッパ、アジア、アフリカにも、岩壁があり条件を満たす場所には分布する。代表的なものとして愛媛県上浮穴(かみうけな)郡久万高原(くまこうげん)町の上黒岩岩陰遺跡、長崎県佐世保市下本山町の下本山岩陰遺跡がある。

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