Yamagiri Prefecture

Yamagiri Prefecture is a southern prefecture in the country of Saharin. It is stated to include all land part of the Yamagiri River watershed, though that is not entirely accurate. It does include the entire Yamagiri River and all major tributaries as well as the entirety of Ebisu-ura's shoreline and the entirety of the Kimura peninsula.

The Population of Yamagiri Prefecture is about 415,000. Not including Eimei-shi, which is it's own prefecture in terms of being nationally represented, Yamagiri Prefecture is the most densely populated prefecture and the only prefecture with two major cities.
The municipalities in Yamagiri Prefecture include:
Okinami, the administrative seat, population ~190,000, Saharin's third largest city.
Kimura, a major port, population ~160,000, Saharin's fourth largest city.
Yuren Futou (ゆれん埠頭) is part of Kimura, but often listed separately because it is primarily the naval base. The base may have ~3,000 people associated with it.
Chōseki (長石), population ~15,000, administratively includes mines and farming communities. It also includes Tendo, Inomura and Sekkaigan as part of it's Lower House district.
Ono-Ore (斧折れ), population ~10,000. Sakeura, Kihana Tani and Aisaya are included in Ono-Ore's Lower House district.
Sakeura (鮭浦), population ~10,000, administratively includes the village of Kihana Tani (木肌谷). The only airport in Yamagiri Prefecture is in Kihana Tani. It is an Air Force base, but does include a private plane hanger (primarily for reservists and retired Air Force) and accepts some commercial deliveries. Air Force personnel may account for an additional 3,000 people.
Tendo (天堂町), population ~10,000, administratively includes many unnamed farming communities. Tendo is part of Choseki's Lower House district.
Aisaya (秋沙鸭), population ~8,000, administratively includes the village of Nakamura (中村) and many unnamed farming communities.
Inomura (猪村), population ~3,000, administratively includes many unnamed farming communities.
Sekkaigan (石灰岩), population ~3,000, administratively includes mines and some other mountain communities.

Yamagiri River (山切り川)
Yamagiri River is the backbone of Yamagiri Prefecture. It flows out of the mountains in the north of the prefecture and is fed by a network of tributaries before finally flowing out in to the Sea of Japan at a bay near Kimura. There is a system of dams and locks that improve water travel, reduce flooding, and supply much of the electricity for Yamagiri Prefecture.