所在地：山鹿市城字西福寺
指定日：大正11年10月12日（国史跡）
墳 形：前方後円墳
説 明：古墳時代後期（６世紀）頃に造られた装飾古墳
チブサン古墳は、古墳時代後期（６世紀）に造られたお墓です。
古墳は前方後円墳で、その後円部の内部に割り石を積み上げて作られた部屋（石室－せきしつ）が造られています。その石室の奥に石の棺おけ（石棺－せっかん）が置かれてあります。
石棺の壁には赤、白、黒の三色で、丸や三角、菱形などの図が描かれていています。正面の二つ並んだ円が女性の乳房に見えることから「チブサン」という名がついたと言われています。
保存状態がとても良好で、熊本はもとより日本の装飾古墳を代表する古墳の一つとされます。
チブサン古墳内部見学について
土・日曜・祝日 １０時と１４時 各１０名と制限させていただきます。
ご見学を希望される場合は、事前に山鹿市立博物館へ予約し、見学時間１０分前までに博物館へ見学料をお支払いください。
申込先
山鹿市立博物館（開館時間：午前9時から午後５時まで 休館日：月曜・祝日の翌日・年末年始）
TEL：０９６８－４３－１１４５
FAX：０９６８－４３－１１４３
メール：bunka@city.yamaga.kumamoto.jp
住所：熊本県山鹿市鍋田２０８５
※メール・Faxでのお申込みの場合、希望日時、見学者数、博物館への交通手段、連絡先(携帯等)を記載下さい。
見学料
個人(１４名以下) 一般・大学生１００円 高校生以下５０円
団体(１５名以上) 一般・大学生 ６０円 高校生以下３０円
注意事項
※チブサン古墳まで自力で行ける方に限ります。博物館からチブサン古墳までは約1km(車2分・徒歩15分)あります。
※チブサン古墳内部入口は大変狭いため（高さ約８０センチ、幅約５０センチ）、入退場時は身をかがめる必要があります。また、その際服が汚れることがあります。ご了承ください。
外部リンク
Chibusan Burial Mound
Colorful geometric patterns and a humanlike figure decorate the inner chambers of the Chibusan Burial Mound, which dates from the Kofun period (mid-3rd to late 7th century). The term kofun means “ancient burial mound” and refers to the tombs that were built for members of the ruling class during this time.
From the outside, the burial mound has the appearance of two small hills approximately 55 meters in length. It contains a burial chamber made of rocks stacked up to nearly 4 meters high.
Ancient symbols and colors
The burial chamber is built from large slabs of stone, measuring 2.3 meters in length, 0.9 meters in depth, and 1.45 meters in height. The slabs are painted with geometric patterns in vivid red, white, and black. The red color was applied using burnt soil rich in iron oxide, while clay and manganese were used for the white and black colors. Numerous triangular shapes immediately draw the eye; archaeologists believe these may have been intended to ward off evil spirits. Two white circles with black dots are painted in the center of the chamber wall. These shapes have been alternately explained as stars, mirrors, or breasts.
On the adjoining slab to the right is a humanlike figure with outstretched arms and what appears to be a crown on its head. Seven circles are painted in the space above it. Some believe these circles may represent the seven stars of the Big Dipper constellation.
Vestiges of history nearby
No bodies or artifacts are known to have been found in the chamber interior. A stone sculpture of a human figure measuring 150 centimeters high and 80 centimeters wide was discovered nearby, however. It was possibly placed there to protect the tomb. The original statue is held at the Tokyo National Museum, and a replica is displayed beside the mound.
The Chibusan Burial Mound is located less than 10 minutes to the west of Yamaga by car. The access road is narrow and large vehicles may not be able to easily reach the area. The outdoor site and an open-air re-creation of the inner chamber’s sarcophagus can be visited at any time. However, the interior can be viewed only on weekends and holidays at 10:00 a.m. and 2:00 p.m., and advance reservations are required. (For inquiries, please contact: bunka@city.yamaga.kumamoto.jp) The innermost chamber of the mound can be seen only through a window.
At a separate site nearby, there is a series of 61 chambers dug into a section of rocky hillside. These have been dubbed the Nabeta Caves. They also date to the Kofun period and may have served as tombs. For more about burial mounds, the Kumamoto Prefectural Decorated Tumulus Museum in Yamaga offers detailed information and extensive exhibitions about this cultural practice. (https://kofunkan.pref.kumamoto.jp/en/guide/)