Lake Biwa in the context of "Hepburn romanization"

Honshu (Japanese: 本州, Hepburn: Honshū; pronounced [hoꜜɰ̃.ɕɯː] ; lit. 'main province'), historically known as Akitsushima (秋津島; lit. 'dragonfly island'), is the largest of Japan's four main islands. It lies between the Pacific Ocean (east) and the Sea of Japan (west). It is the seventh-largest island in the world, and the second-most populous after the Indonesian island of Java.

Honshu had a population of 104 million as of 2017, constituting 81.3% of the entire population of Japan, and mostly concentrated in the coastal areas and plains. Approximately 30% of the total population resides in the Greater Tokyo Area on the Kantō Plain. As the historical center of Japanese cultural and political power, the island includes several past Japanese capitals, including Kyoto, Nara, and Kamakura. Much of the island's southern shore forms part of the Taiheiyō Belt, a megalopolis that spans several of the Japanese islands. Honshu also contains Japan's highest mountain, Mount Fuji, and its largest lake, Lake Biwa.

Shiga Prefecture (滋賀県, Shiga-ken; Japanese pronunciation: [ɕiꜜ.ɡa, -ŋa, ɕi.ɡaꜜ.keɴ, -ŋaꜜ.keɴ]) is a landlocked prefecture of Japan in the Kansai region of Honshu. Shiga Prefecture has a population of 1,398,972 as of 1 February 2025 and has a geographic area of 4,017 km (1,551 sq mi). Shiga Prefecture borders Fukui Prefecture to the north, Gifu Prefecture to the northeast, Mie Prefecture to the southeast, and Kyoto Prefecture to the west.

Ōtsu is the capital and largest city of Shiga Prefecture, with other major cities including Kusatsu, Nagahama, and Higashiōmi. Shiga Prefecture encircles Lake Biwa, the largest freshwater lake in Japan, and 37% of the total land area is designated as Natural Parks, the highest of any prefecture. Shiga Prefecture's southern half is located adjacent to the former capital city of Kyoto and forms part of Greater Kyoto, the fourth-largest metropolitan area in Japan. Shiga Prefecture is home to Ōmi beef, the Eight Views of Ōmi, and Hikone Castle, one of four national treasure castles in Japan.

Uji (宇治市, Uji-shi) is a city on the southern outskirts of the city of Kyoto, in Kyoto Prefecture, Japan.

Founded on March 1, 1951, Uji is between the two ancient capitals of Nara and Kyoto. The city sits on the Uji River, which has its source in Lake Biwa.

Ōmi Province (近江国, Ōmi no Kuni; Japanese pronunciation: [oꜜː.mʲi (no kɯ.ɲi)]) was a province of Japan, which today comprises Shiga Prefecture. It was one of the provinces that made up the Tōsandō circuit. Its nickname is Gōshū (江州). Under the Engishiki classification system, Ōmi was ranked as one of the 13 "great countries" (大国) in terms of importance, and one of the "near countries" (近国) in terms of distance from the imperial capital Kyoto.

Ōmi bordered on Wakasa and Echizen Provinces to the north, Mino and Ise Provinces to the east, Iga and Yamato Provinces to the south, and Yamashiro and Tanba Provinces to the west. Lake Biwa, Japan's largest lake, is located at the center of the province.

Azuchi Castle (安土城, Azuchi-jō) was one of the primary castles of Oda Nobunaga located in the Azuchi neighborhood of the city of Ōmihachiman, Shiga Prefecture. The site of the castle was designated a National Historic Site in 1926, with the designation upgraded to that of a Special National Historic Site in 1952. The castle is located within the grounds of the Biwako Quasi-National Park.

Azuchi Castle was built from 1576 to 1579 on Mount Azuchi on the eastern shore of Lake Biwa in Ōmi Province. Nobunaga intentionally built Azuchi Castle close enough to Kyoto that he could watch over and guard the approaches to the capital, but outside Kyoto so his fortress would be immune to the fires and conflicts that occasionally consumed the city. Azuchi Castle's location was also strategically advantageous in managing the communications and transportation routes between Nobunaga's greatest foes – the Uesugi to the north, the Takeda in the east, and the Mōri to the west. Azuchi Castle was demolished in 1582 by Akechi Mitsuhide after his assassination of Nobunaga in the Honno-ji Incident.

Kusatsu (草津市, Kusatsu-shi) is a city located in Shiga Prefecture, Japan. The city lies on Lake Biwa, Japan's largest freshwater lake. As of 31 January 2024, the city had an estimated population of 139,913 in 63,942 households and a population density of 2100 persons per km. The total area of the city is 67.82 square kilometres (26.19 sq mi). The city is often confused with Kusatsu, Gunma Prefecture, which is a famous hot spring resort.

The Yodo River (淀川, Yodo-gawa), also called the Seta River (瀬田川 Seta-gawa) and the Uji River (宇治川 Uji-gawa) at portions of its route, is the principal river in Osaka Prefecture on Honshu, Japan. The source of the river is Lake Biwa in Shiga Prefecture to the north.

The Yodo River, usually called the Seta River in Shiga Prefecture, begins at the southern outlet of the lake in Ōtsu. There is a dam there to regulate the lake level. Further downstream, the Seta flows into Kyoto Prefecture and its name changes to the Uji River. It then merges with two other rivers, the Katsura River and the Kizu River in Kyoto Prefecture. The Katsura has its headwaters in the mountains of Kyoto Prefecture, while the Kizu comes from Mie Prefecture. From the three-river confluence, the river is called the Yodo River, which flows south, through Osaka, and on into Osaka Bay. In Osaka, part of the river has been diverted into an artificial channel; the old course in the heart of Osaka is called the Kyū-Yodo River (literally, 'Former Yodo River'). It serves as a source of water for irrigation and also powers hydroelectric generators.