Latest news with #Nanbokucho
The Mainichi
08-07-2025
- Science
- The Mainichi
News in Easy English: Old castle found in Hyogo mountains by using AI maps
KOBE -- A small, old castle was found in the mountains of Hyogo Prefecture in March. Researchers found the castle using artificial intelligence (AI). The castle was probably built about 700 years ago in the 14th century, during Japan's Nanbokucho period (1336-1392). It's on top of a mountain, about one hour by foot from the nearest road. Because of the shape of the mountain around it, researchers believe the castle was used as a lookout to watch over the area. Researchers found the castle by using new 3D maps from Hyogo Prefecture. The maps show the ground's shape very clearly. AI studied the maps first to look for old Japanese tombs called "kofun." When scientists checked the places found by AI, they discovered some new sites, including this castle site. Lead researcher Yuichi Takata said, "There may be even more old castles around this area. We hope this will help us understand history better." Using AI and 3D maps, people are starting to find more ancient places in Japan's mountains. Usually, it is difficult to find such places just by walking and looking around. But clear map data can help people find these sites much faster. Researchers say, "This new way of finding old places is very useful, both for studying history and for checking before building new roads and towns." (Japanese original by Akira Inoh, Kobe Bureau) Vocabulary castle: a big, strong building where people lived and fought a long time ago researcher: a person who studies something carefully map data: information showing details of roads or land on a map site: a place where something important was built or happened long ago lookout: a high place where people watch for danger or people coming near ancient: very old; from a long time ago tomb: a place in the ground made for dead people three-dimensional (3D): showing something clearly with height, width and deepness (not flat) period: an amount of time in history prefecture: an area in Japan with its own local government
The Mainichi
04-05-2025
- Science
- The Mainichi
AI helping researchers, laypeople discover archaeological sites in Japan mountains
KOBE -- Traces of a small mountain castle dating to medieval times were discovered in the hills of Tatsuno, Hyogo Prefecture, this March, thanks to advances in surveying powered by artificial intelligence (AI). Are new methods ushering in a new era of discoveries? What led to the find was highly precise 3D map data published by Hyogo Prefecture. The hill castle ruins' location was confirmed when a research team from the Nara National Research Institute for Cultural Properties (Nabunken) found distinctive landforms at the site which were first seen in an AI-driven map analysis during other research. The ruins were found near a peak about an hour's walk from a road. One of its slopes is flattened, and landform features such as traces of a moat and a bridge were seen there. The height from the bottom of the moat to the flattened area is estimated to have reached 5 meters. Since remnants of roads were also found nearby, it was concluded to be highly probable the castle was a lookout. Since it is not built robustly enough as a base for battle, as those in the Sengoku (Warring States) period (1467-1615), the site is thought to date back to the 14th century Nanbokucho period (1336-1392) when mountain fortresses were still developing. Four kilometers northeast, the Kinoyama Castle Ruins sit where the Akamatsu clan, a powerful family in Harima Province at the time, had their base of operations. Lead researcher Yuichi Takata, a Nabunken historian who made the discovery, said, "Many distinctive landforms were also found in the surrounding area that could have been mountain castle sites. If these are connected, it may help to map out the possible power relationships of the time." Use of aerial lasers Takata and the others utilized 3D map data covering all of Hyogo Prefecture, which the prefectural government began releasing to the public in stages in 2020. The data, measured by aerial laser scanning, provides elevation in square areas 1 meter on each side in flat areas and square areas 50 centimeters on a side in mountainous regions. They used AI to analyze the data as part of research to locate ancient Japanese burial mounds known as kofun. At least 1,300 locations with land features that could indicate ancient burial mounds were found, and on-site surveys in locations in the cities of Toyooka and Tatsuno confirmed 34 as burial mounds and temple ruins. This was reportedly when the unusual landform was observed, which was later determined to be the site of a mountain castle. Ancient sites found in the mountains one after another Under the Act on Protection of Cultural Properties, development projects near previously discovered sites must be reported as the surrounding areas are designated as "areas containing cultural properties." The Agency for Cultural Affairs says there are about 460,000 such sites nationwide, with around 9,000 excavations conducted annually. However, most of these surveys are linked to development, and are therefore concentrated in urban areas. Mountainous areas can be seen as a void for archaeological excavation, but in recent years, the trend is changing as governments successively make map data available to the public and archaeology fans are starting to use it to make discoveries. In Hida, Gifu Prefecture, the city government started utilizing map data in fiscal 2019. Thanks to suggestions from archaeology fans, burial mounds, mountain fortresses and other structures have been discovered, and inspired city staff analyzed the data and newly registered 71 archaeological sites. The Geospatial Information Authority of Japan has been publicly releasing map data since 2023. At the end of this past March, the data covered around 40% of the entire country. Also in 2023, the Hyogo Prefectural Government released geodata with a resolution of 50 centimeters on each side. The high accuracy makes it possible to spot ruins not only using AI, but also with the naked eye. "Ruins are often located deep in the mountains, and it's difficult to find them by raw effort alone. If they can be identified in advance using 3D maps, that makes it an order of magnitude more efficient," said Takata. Hyogo Prefectural Museum of Archaeology curator Hirokazu Nagae, who worked on the findings with Takata, commented, "Searching for archaeological sites from 3D maps is becoming popular overseas. It looks like it can be used effectively not only for research and as a hobby, but also for surveys associated with development." (Japanese original by Akira Inoh, Kobe Bureau)
