| Nanmoku | |
| Native Name Lang: | ja |
| Settlement Type: | Village |
| Pushpin Map: | Japan |
| Pushpin Map Caption: | |
| Coordinates: | 36.1585°N 138.7114°W |
| Subdivision Type: | Country |
| Subdivision Name: | Japan |
| Subdivision Type1: | Region |
| Subdivision Name1: | Kantō |
| Subdivision Type2: | Prefecture |
| Subdivision Name2: | Gunma |
| Subdivision Type3: | District |
| Subdivision Name3: | Kanra |
| Leader Title: | Mayor |
| Area Total Km2: | 118.83 |
| Population Total: | 1746 |
| Population As Of: | August 2020 |
| Population Density Km2: | auto |
| Timezone1: | Japan Standard Time |
| Utc Offset1: | +9 |
| Blank Name Sec1: | Symbols |
| Blank Info Sec1: | |
| Blank1 Name Sec1: | • Tree |
| Blank1 Info Sec1: | Cryptomeria |
| Blank2 Name Sec1: | • Flower |
| Blank3 Name Sec1: | • Bird |
| Blank3 Info Sec1: | Japanese bush-warbler |
| Blank Name Sec2: | Phone number |
| Blank Info Sec2: | 0274-87-2111 |
| Blank1 Name Sec2: | Address |
| Blank1 Info Sec2: | 1089 Dainichimukai, Namoku-mura, Kanra-gun, Gunma-ken 370-2601 |
right|thumb|250px|Semi Valley ravine is a village located in Gunma Prefecture, Japan., the village had an estimated population of 1,746 in 971 households,[1] and a population density of 15 persons per km². The total area of the village is 118.83sqkm.
Nanmoku, like many rural areas in Japan, has witnessed significant population decline since the mid-20th century. As of 2023, 67.5% of the population was over age 65 and the median age was 68.4, making Nanmoku the grayest village in Japan.[2]
Nanmoku is located in southwestern Gunma Prefecture bordering on Nagano Prefecture to the west. Part of the village is within the borders of the Myōgi-Arafune-Saku Kōgen Quasi-National Park.
Nanmoku has a humid continental climate (Köppen Cfa) characterized by warm summers and cold winters with heavy snowfall. The average annual temperature in Nanmoku is 11.0 °C. The average annual rainfall is 1127 mm with September as the wettest month. The temperatures are highest on average in August, at around 24.0 °C, and lowest in January, at around -1.3 °C.[3]
Per Japanese census data,[4] the population of Nanmoku peaked around the year 1950 and has decreased drastically since then. As of 2023, 67.5% of the population is 65 or older, making Nanmoku the oldest village in Japan.[2]
During the Edo period, the area of present-day Nanmoku was largely part of the tenryō territory held directly by Tokugawa shogunate within Kōzuke Province. The area was divided into villages with the establishment of the modern municipalities system on April 1, 1889. The village of Nanmoku was created on March 15, 1955 by the merger of the villages of Iwado, Tsukigata and Ozawa.
Nanmoku has a mayor-council form of government with a directly elected mayor and a unicameral village council of eight members. Nanmoku, together with the other municipalities in Kanra District contributes one member to the Gunma Prefectural Assembly. In terms of national politics, the town is part of Gunma 5th district of the lower house of the Diet of Japan.
During the postwar decades Nanmoku had a thriving economy anchored by sericulture, konjac cultivation and forestry. However, by the late 20th century konjac production had relocated to more economical areas while Nanomku's silk and forest products struggled to compete with cheap foreign imports. The lack of economic opportunity accelerated Nanmoku's population decline, further weakening the economy. In the present day, economic activity in Nanmoku is centered around services and small-scale agriculture.[2]
Nanmoku has a nursery school, compulsory school operated by the village government.[5] The village does not have a high school.
Nanmoku is not served by any passenger railway service. The nearest train station is Shimonita Station in the neighboring town of Shimonita.
Nanmoku is not served by any national highways.
Nanmoku is popular locally for its scenery. The village is located in the valley of a small mountain range, where there are excellent hiking opportunities. One of the mountains, Mt. Arahune, is home to a park with a campsite, including a large multipurpose recreational area that has tennis, water sports, and fishing facilities. There is also an astronomy center located on the grounds. Nanmoku also has a museum that documents local culture and history.
thumb|150px|right|Nanmoku's fire-spinning festival, hitoboshi.The village is particularly famous for, the two-day local fire festival, the largest in the prefecture.[6] Many people who have moved away but still have family in the village return for this festival, and it is popular with tourists as well. Though such fire festivals were once popular, few remain. Nanmoku's version falls on August 14 and 15, and coincides with Obon, a festival honoring ancestors. However, Hitoboshi itself commemorates the village's victorious alliance with the Takeda clan during the Sengoku period.[7] During the festival, villagers take turns standing on a bridge and twirling burning bales of hay over the edge.