Tama Hills

A hilly region in the southern Kanto region, stretching between the Tama River and the Sakai River. It stretches from the foot of Mount Takao in the northwest to Yokohama City in the southeast. Topographically, the northeastern side of the hill is the Tama River lowland and the Musashino Plateau, while the western side is the Sakai River and the Sagamihara Plateau. The northwestern area south of Hachioji is the highest at around 220 meters, and gradually becomes lower towards the southeast. Around Mizonokuchi, it becomes a lower plateau made up of the Shimosueyoshi Formation, and in the upland area of ​​Yokohama City it is 40 to 50 meters high, facing Tokyo Bay via sea cliffs. The hill surface has been eroded and is very undulating.

There are Jomon period ruins on the hills, and numerous Yayoi and Kofun period ruins on the slopes and at the base of the hills, so it is known that the area has been open since prehistoric times. In ancient times, the Tokaido road passed through the area, and the nearby areas were used for the Ishikawa and Tateno pastures. From the end of the Heian period, the Yokoyama, Nishi, and Tsuzuku (Tsuzuki) clans of the Musashi Seven Clans developed the area, and in the Kamakura and Muromachi periods, the Kamakura Kaido road passed through the center and southeast of the hills, and the remains of ancient battlefields can also be seen. In the Edo period, the Nakahara, Yagurazawa, and Tsukui highways connected Edo with the Tokai region and Koshu. In the Meiji era, the area was converted into mulberry fields along with the Sagamihara Plateau and became a silkworm-raising region, and in the Showa era, the Odakyu Electric Railway Odawara Line was opened in the center, the Tokyu Electric Railway Denentoshi Line and the Third Keihin Highway were opened in the southeast, and with the development of Tama New Town progressing, the Keio Electric Railway Sagamihara Line and the Odakyu Electric Railway Tama Line were opened in the north from 1974 (Showa 49) to 1990 (Heisei 2), and the Tama Toshi Monorail was also opened in 2000 (Heisei 12). It is also a major transportation route connecting the east and west of Japan, with the Tokaido-Sanyo Shinkansen and Tomei Expressway passing through the south, and Shin-Yokohama Station and the Kawasaki, Yokohama-Aoba and Yokohama-Machida interchanges serving as transportation hubs. As a result, the Tama Hills near the Keihin area are home to many universities' main campuses and branch campuses and research institutes, as well as Tama New Town, several large housing complexes, golf courses, Tama Zoo, Yomiuri Land, and Kodomo no Kuni, and are rapidly transforming into an educational, cultural, residential and recreational district of the Keihin urban area.

[Yukio Asaka]

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

関東地方の南部、多摩川と境川(さかいがわ)との間に広がる丘陵。北西は高尾山麓(さんろく)から、南東は横浜市まで延びている。地形的には、丘陵の北東側は多摩川低地で武蔵野台地(むさしのだいち)と、西側は境川で相模原台地(さがみはらだいち)と区別される。北西部の八王子の南が220メートル内外でもっとも高く、南東へ向かってしだいに低くなる。溝口(みぞのくち)付近からは下末吉(しもすえよし)層からなる一段低い台地となり、横浜市の山手では40～50メートルとなり、海食崖(がい)で東京湾に臨む。丘陵面は侵食されて起伏に富んでいる。

　丘陵上には縄文時代遺跡、斜面から脚部には弥生(やよい)時代や古墳時代の遺跡が多数みられて、先史時代から開けていたことが知られる。そして古代には東海道が通じ、その近くが石川・立野(たての)両牧(まき)にあてられていた。平安末期からは武蔵七党の横山、西、綴(つづき)（都筑）諸氏による開拓が行われ、鎌倉・室町時代には丘陵の中央部と南東部には鎌倉街道が通じ、古戦場跡もみられる。江戸時代には江戸と東海地方や甲州とを結ぶ中原、矢倉沢(やぐらさわ)、津久井(つくい)の諸往還が通じていた。明治に入ると相模原台地とともに桑園化されて養蚕地域となり、昭和時代には、中央部に小田急電鉄小田原線、南東部に東急電鉄田園都市線、第三京浜道路が開通し、多摩ニュータウンの開発進展に伴い1974年（昭和49）から1990年（平成2）に北部に京王電鉄相模原線と小田急電鉄多摩線が開通、2000年（平成12）には多摩都市モノレールも通じた。また、ここは日本の東西連絡の交通幹線の通路にもあたり、南部に東海道・山陽新幹線、東名高速道路が通じ、新横浜駅、川崎・横浜青葉・横浜町田各インターチェンジは交通拠点となっている。こうして京浜の近郊にある多摩丘陵には諸大学の本・分校舎や研究所、多摩ニュータウンをはじめ、いくつもの大規模住宅団地やゴルフ場、多摩動物公園、よみうりランド、こどもの国などがつくられ、京浜都市群の教育・文化・住宅・レクリエーション地区として大きく変わりつつある。

［浅香幸雄］

出典　小学館　日本大百科全書(ニッポニカ)日本大百科全書(ニッポニカ)について　情報 | 凡例