Aomori Prefecture in the context of "Tōhoku region"

The Northeastern Japan Arc, also Northeastern Honshū Arc, is an island arc on the Pacific Ring of Fire. The arc runs north to south along the Tōhoku region of Honshū, Japan. It is the result of the subduction of the Pacific plate underneath the Okhotsk plate at the Japan Trench. The southern end of the arc converges with the Southwestern Japan Arc and the Izu–Bonin–Mariana Arc at the Fossa Magna (ja) at the east end of the Itoigawa-Shizuoka Tectonic Line (ITIL). This is the geologic border between eastern and western Honshū. Mount Fuji is at the point where these three arcs meet. To the north, the Northeastern Japan arc extends through the Oshima Peninsula of Hokkaidō. The arc converges in a collision zone with the Sakhalin Island Arc and the Kuril Island Arc in the volcanic Ishikari Mountains of central Hokkaidō. This collision formed the Teshio and Yūbari Mountains.

The Ōu Mountains form the backbone of the volcanic part of the inner arc that run from Natsudomari Peninsula in Aomori Prefecture south to Mount Nikkō-Shirane in Tochigi and Gunma prefectures. The volcanic front consists of four north to south lines of Quaternary volcanoes and calderas, which extend the length of the range. It also includes the Quaternary volcanoes of southwestern Hokkaido. The Dewa Mountains and the Iide Mountains are non-volcanic uplift ranges that run parallel to the west of the Ōu Mountains.

The Tsugaru Strait (津軽海峡, Tsugaru Kaikyō) is a strait between Honshu and Hokkaido in northern Japan connecting the Sea of Japan with the Pacific Ocean. It was named after the western part of Aomori Prefecture. The Seikan Tunnel passes under it at its narrowest point 12.1 miles (19.5 km) between Tappi Misaki on the Tsugaru Peninsula in Aomori Prefecture, Honshu, and Shirakami Misaki on the Matsumae Peninsula in Hokkaido.

Western maps made prior to the 20th century also referred to this waterway as the Strait of Sangar.

The Seikan Tunnel (Japanese: 青函トンネル, Seikan Tonneru or 青函隧道, Seikan Zuidō) is a 53.85-kilometre (33.5-mile) dual-gauge railway tunnel in Japan, with a 23.3-kilometre (14.5-mile) segment running beneath the seabed of the Tsugaru Strait, which separates Aomori Prefecture on Honshu, Japan's main island, from the northern island of Hokkaido. The tunnel's track level lies approximately 100 metres (330 ft) below the seabed and 240 metres (790 ft) below sea level. Following several decades of planning and construction, the tunnel opened on 13 March 1988.

The Seikan Tunnel forms part of the standard-gauge Hokkaido Shinkansen as well as the narrow-gauge Kaikyō Line operated by the Hokkaido Railway Company (JR Hokkaido). Its name, "Seikan," is derived from the on'yomi readings of the first characters of Aomori (青森), the nearest major city in Honshu, and Hakodate (函館), the nearest major city in Hokkaido.

Mutsu Province (陸奥国, Mutsu no Kuni; Japanese pronunciation: [mɯꜜ.tsɯ (no kɯ.ɲi)]) was an old province of Japan in the area of Fukushima, Miyagi, Iwate and Aomori Prefectures and the municipalities of Kazuno and Kosaka in Akita Prefecture.

Mutsu Province is also known as Ōshū (奥州) or Michinoku (陸奥 or 道奥). The term Ōu (奥羽) is often used to refer to the combined area of Mutsu and the neighboring province Dewa, which together make up the entire Tōhoku region.

The Ōu Mountains (奥羽山脈, Ōu-sanmyaku) are a mountain range in the Tōhoku region of Honshū, Japan. It is the longest range in Japan and stretches 500 km (311 mi) south from the Natsudomari Peninsula of Aomori Prefecture to the Nasu volcanoes at the northern boundary of the Kantō region. Though long, the range is only about 35 kilometres (22 mi) wide. The highest point in the range is Mount Iwate, 2,038 metres (6,686 ft).

The range includes several widely known mountains: Hakkōda Mountains, Mount Iwate, Mount Zaō, Mount Azuma, Mount Yakeishi, and Mount Adatara.

Dewa Mountains (Japanese: 出羽山地) is a mountain range that runs north and south on the west side of the Tohoku region of Japan. The mountain range spans Aomori, Akita, and Yamagata prefectures. The Dewa Mountains are split into several sub-ranges by the Yoneshiro River, the Omono River and the Mogami River. These sub-ranges include the Shirakami Mountains, the Tahei Mountains, The Choki Mountains, and the Chotake Mountains.The highest peak of the mountain range is Mount Chokai (2,236m).

Akita Prefecture (秋田県, Akita-ken; Japanese pronunciation: [aꜜ.kʲi̥.ta, a.kʲi̥.taꜜ.keɴ]) is a prefecture of Japan located in the Tōhoku region of Honshu. Its population is estimated 915,691 as of 1 August 2023 and its geographic area is 11,637 km (4,493 sq mi). Akita Prefecture is bordered by Aomori Prefecture to the north, Iwate Prefecture to the east, Miyagi Prefecture to the southeast, and Yamagata Prefecture to the south.

Akita is the capital and largest city of Akita Prefecture. Other major cities include Yokote, Daisen, and Yurihonjō. Akita Prefecture is located on the coast of the Sea of Japan and extends east to the Ōu Mountains, the longest mountain range in Japan, at the border with Iwate Prefecture. Akita Prefecture formed the northern half of the historic Dewa Province with Yamagata Prefecture.

Iwate Prefecture (岩手県, Iwate-ken; Japanese pronunciation: [iꜜ.wa.te, i.wa.teꜜ.keɴ]) is a prefecture of Japan located in the Tōhoku region of Honshu. It is the second-largest Japanese prefecture (behind Hokkaido) at 15,275 square kilometres (5,898 sq mi), with a population of 1,165,886 (as of July 1, 2023). Iwate Prefecture borders Aomori Prefecture to the north, Akita Prefecture to the west, and Miyagi Prefecture to the south.

Morioka is the capital and largest city of Iwate Prefecture; other major cities include Ichinoseki, Ōshū, and Hanamaki. Located on Japan's Pacific Ocean coast, Iwate Prefecture features the easternmost point of Honshu at Cape Todo, and shares the highest peaks of the Ōu Mountains—the longest mountain range in Japan—at the border with Akita Prefecture. Iwate Prefecture is home to famous attractions such as Morioka Castle, the Buddhist temples of Hiraizumi including Chūson-ji and Mōtsū-ji, the Fujiwara no Sato movie lot and theme park in Ōshū, and the Tenshochi park in Kitakami known for its huge, ancient cherry trees. Iwate has the lowest population density of any prefecture outside Hokkaido, 5% of its total land area having been designated as national parks.