Mount Fuji stands at 3,776 meters, making it the highest point in Japan. The mountain last erupted in 1707 during the Edo period, depositing ash on Tokyo, then called Edo, over 100 kilometers away. The summit contains a crater approximately 500 meters in diameter. Climbers access the mountain primarily during July and August when stations along four main routes operate. The Yoshida Trail from Yamanashi Prefecture carries approximately 60 percent of all climbers. UNESCO designated Mount Fuji a World Heritage site in 2013 under the cultural category rather than natural, citing its influence on art and religion. The mountain appears in Katsushika Hokusai's woodblock print series "Thirty-Six Views of Mount Fuji" produced between 1830 and 1832. Shinto shrines at the base include Fujisan Hongū Sengen Taisha in Fujinomiya, rebuilt in its current form in 1604. The mountain's snowcap typically forms in early October and melts by late May. Five lakes at the northern base — Kawaguchi, Yamanaka, Sai, Shoji, and Motosu — formed from lava flows that dammed rivers. Lake Motosu appears on the reverse of the 1,000 yen note issued since 2004.
The Japanese Alps comprise three distinct ranges in central Honshu. The Hida Mountains, called the Northern Alps, contain peaks exceeding 3,000 meters including Mount Hotaka at 3,190 meters. The Kiso Mountains form the Central Alps with Mount Kiso-Komagatake reaching 2,956 meters. The Akaishi Mountains constitute the Southern Alps, where Mount Kita at 3,193 meters ranks as the second highest peak in Japan. The term "Japanese Alps" first appeared in English in 1881 when British mining engineer William Gowland published descriptions of the ranges. Japanese geographer Kojima Usui adopted the name in Japanese writing in 1915. Kamikochi valley sits at 1,500 meters elevation in the Northern Alps within Chubu Sangaku National Park, established in 1934. The Azusa River flows through the valley beneath peaks including Mount Yari, whose pyramidal shape rises to 3,180 meters. Road access to Kamikochi closes from mid-November to late April due to snow. The valley received approximately 1.5 million visitors in 2019. Takayama city at the western edge of the Northern Alps served as the administrative center for the Hida region during the Tokugawa shogunate.
The Kanto Plain extends across approximately 17,000 square kilometers in eastern Honshu, making it the largest lowland area in Japan. Tokyo, Yokohama, and the greater metropolitan region occupy this plain at elevations mostly below 50 meters. The Tone River, Japan's second longest at 322 kilometers, drains the northern portion of the plain. The Edo River branches from the Tone River and flows through eastern Tokyo into Tokyo Bay. Engineers redirected the Tone River eastward to its current mouth at Choshi between 1594 and 1654 to reduce flooding in Edo. The plain sits on alluvial deposits from these rivers and volcanic ash from Mount Fuji and Mount Asama. Mount Asama, an active volcano at the plain's northwestern edge, last produced a significant eruption in 1783 that killed approximately 1,400 people. The plain experiences approximately 1,500 millimeters of rainfall annually, concentrated in June and September. Rice cultivation dominated land use until urban expansion accelerated after 1923 following the Great Kanto Earthquake.
Lake Biwa occupies 670 square kilometers in Shiga Prefecture, making it Japan's largest freshwater lake. The lake reaches a maximum depth of 104 meters in the northern basin. Geologists estimate the lake formed approximately 4 million years ago, making it one of the oldest lakes globally. The Yodo River drains the lake southward toward Osaka Bay, descending through Kyoto Prefecture. Lake Biwa supplies drinking water to approximately 14 million people in the Kansai region. The lake contains approximately 60 endemic species including the biwa catfish and the isaza icefish. Commercial fishing yields approximately 1,000 tons annually, with catches dominated by crucian carp. Otsu city on the southwestern shore served as the capital of Omi Province during the seventh century. The Tokaido railway line runs along the eastern shore connecting Tokyo and Osaka. Water quality declined during the 1960s and 1970s due to industrial discharge and agricultural runoff. Shiga Prefecture enacted Japan's first phosphate detergent ban in 1979, reducing algae blooms by the 1990s.
Hokkaido, the northernmost main island, contains multiple mountain ranges and volcanic peaks. The Daisetsuzan volcanic group in central Hokkaido includes Mount Asahi at 2,291 meters, the highest point on the island. Daisetsuzan National Park, established in 1934, covers 2,267 square kilometers. The Hidaka Mountains run north-south along the island's southern central region with peaks reaching approximately 2,000 meters. The Ishikari Plain in western Hokkaido extends approximately 4,000 square kilometers, supporting Sapporo and surrounding agricultural areas. The Tokachi Plain in southeastern Hokkaido covers approximately 3,600 square kilometers, producing significant wheat, potato, and dairy outputs. Hokkaido's volcanic activity continues at peaks including Mount Usu, which erupted in 2000, and Mount Tokachi, which produced steam explosions in 1988 and 1989. The Shiretoko Peninsula extends into the Sea of Okhotsk in northeastern Hokkaido. UNESCO designated Shiretoko a World Heritage site in 2005, citing marine and terrestrial ecosystem connections. Brown bears inhabit the peninsula with a population estimated at approximately 500 individuals. Sea ice from the Okhotsk reaches the peninsula's coast between January and March, supporting ice-associated algae that sustain the food chain. The Shiretoko mountain range runs along the peninsula's spine with peaks including Mount Rausu at 1,661 meters.
The Inland Sea, called Setonaikai in Japanese, separates Honshu, Shikoku, and Kyushu islands. The sea extends approximately 450 kilometers east-west and varies between 15 and 55 kilometers in width. The sea contains approximately 3,000 islands, most uninhabited. Geologists attribute the sea's formation to tectonic subsidence during the Quaternary period. The Akashi Strait between Honshu and Awaji Island narrows to approximately 4 kilometers. The Great Seto Bridge, completed in 1988, connects Okayama Prefecture on Honshu to Kagawa Prefecture on Shikoku across a distance of 13.1 kilometers using five bridges and intervening islands. The sea's maximum depth reaches approximately 105 meters in the Bisan Strait. Tidal currents in narrow channels including the Naruto Strait between Awaji Island and Shikoku reach speeds exceeding 4 meters per second. These currents create whirlpools with diameters up to 20 meters during spring tides. The sea historically supported intensive fishing including sardines, anchovies, and Spanish mackerel. Industrial development along coastal areas during the 1950s and 1960s degraded water quality. Dissolved oxygen concentrations in bottom waters declined, causing red tides. The Inland Sea Environmental Conservation Special Measures Law enacted in 1973 restricted phosphorus and nitrogen discharges from industrial and municipal sources.
Miyajima Island, officially named Itsukushima, sits in the Inland Sea approximately 10 kilometers from Hiroshima city. The island covers 30.4 square kilometers with Mount Misen rising to 535 meters. Itsukushima Shrine, established in its current form in 1168 during the Heian period, extends over tidal flats on the island's northern coast. The shrine's torii gate stands 16 meters high in the water approximately 160 meters offshore. High tide submerges the gate's base while low tide exposes the sand below. Taira no Kiyomori, who controlled the imperial court during the 1160s, sponsored the shrine's reconstruction. UNESCO designated the shrine and the island's forested area a World Heritage site in 1996. Approximately 4 million tourists visit the island annually. Ferry services from Miyajimaguchi on Honshu carry passengers across the strait in approximately 10 minutes. Sika deer inhabit the island with a population estimated at approximately 1,500 individuals. The deer show no fear of humans and consume food items left accessible. Local authorities classify the deer as wild animals without legal protection as designated natural monuments.
The Izu Peninsula extends approximately 60 kilometers southward into the Pacific Ocean from Honshu. The peninsula's width varies between 10 and 30 kilometers. Mount Amagi, the peninsula's highest point, reaches 1,406 meters. The peninsula sits on the Philippine Sea Plate, which moves northwest relative to the Eurasian Plate at approximately 5 centimeters annually. This movement produces earthquakes including the 1930 North Izu earthquake with magnitude 7.3 that killed 272 people. Volcanic activity created the peninsula's topography, with the most recent eruptions occurring approximately 3,000 years ago. The Jogasaki Coast on the eastern shore displays basalt columnar joints from lava flows. Hot springs emerge throughout the peninsula with concentrations in Atami, Ito, and Shimoda. Shimoda city at the southern tip contains two harbors where Commodore Matthew Perry anchored U.S. Navy ships in 1854. The Treaty of Kanagawa, signed that year, designated Shimoda and Hakodate as ports open to American vessels. The peninsula falls within Fuji-Hakone-Izu National Park, designated in 1936. The Izu Islands extend approximately 300 kilometers southward from the peninsula's tip, comprising volcanic islands including Oshima and Hachijojima.
The Noto Peninsula extends approximately 100 kilometers into the Sea of Japan from Ishikawa Prefecture. The peninsula's width varies between 20 and 40 kilometers. The peninsula's northern coast faces northwest, receiving winter winds and waves from Siberia that produce significant precipitation as snow. Annual snowfall in coastal areas exceeds 2 meters. The Okunoto region in the northern peninsula contains scattered fishing villages and terraced rice fields. The Wajima morning market in Wajima city operates daily except the second and fourth Wednesdays of each month. The market traces its origins to the Heian period, making it one of Japan's oldest continuous markets. Senmaida rice terraces near Wajima descend toward the sea across approximately 4 hectares divided into over 1,000 small plots. LED lights illuminate the terraces during winter months for tourism. The peninsula's southern region contains Kanazawa city, which served as the capital of Kaga Domain during the Edo period. Kaga Domain ranked among the wealthiest feudal domains, producing approximately 1 million koku of rice annually. One koku equals approximately 150 kilograms. The domain's wealth supported cultural development including Kutani porcelain production and gold leaf manufacturing. Kanazawa produces over 99 percent of Japan's gold leaf used for decorative purposes.
Kyushu, the southernmost main island, contains active volcanic systems and geothermal features. Mount Aso in central Kyushu contains one of the world's largest calderas, measuring approximately 25 kilometers north-south and 18 kilometers east-west. The caldera formed during four major explosive eruptions between 300,000 and 90,000 years ago. Five volcanic peaks rise within the caldera, including Mount Naka with an active crater approximately 600 meters in diameter. Mount Naka's crater contains a lake that evaporates during periods of increased volcanic gas emission. The crater emits sulfur dioxide at rates reaching several thousand tons daily during active periods. The Aso caldera contains agricultural land and settlements supporting approximately 50,000 residents. Grazing land covers caldera slopes producing beef and dairy products. Aso-Kuju National Park, established in 1934, encompasses the caldera and surrounding highlands. The Kuju mountain range northeast of the Aso caldera contains peaks exceeding 1,700 meters. Mount Kuju reaches 1,791 meters, the highest point on Kyushu.
Mount Sakurajima forms an active volcanic island in Kagoshima Bay on southern Kyushu. The volcano's summit reaches 1,117 meters. Sakurajima connected to the Osumi Peninsula during a 1914 eruption that produced lava flows across the strait. The eruption deposited approximately 3 billion tons of lava. Explosive eruptions currently occur multiple times daily, ejecting ash that falls on Kagoshima city 4 kilometers across the bay. Annual ash fall in Kagoshima exceeds 1,000 tons per square kilometer in some years. Residents clean ash from streets and roofs routinely. Shelters at bus stops protect waiting passengers from falling ash. The volcano's Minamidake crater became active in 1955. The Showa crater on the eastern flank became active in 2006. The Japan Meteorological Agency maintains continuous monitoring with seismometers, GPS stations, and cameras. Scientists recorded over 900 explosive eruptions in 2019. Ferry services operate continuously between Kagoshima city and Sakurajima, carrying vehicles and passengers across the 15-minute route.
The Ryukyu Islands extend approximately 1,200 kilometers southwest from Kyushu toward Taiwan. The chain includes Okinawa Island, the largest at approximately 1,200 square kilometers. Okinawa Island reaches a maximum width of approximately 30 kilometers and extends approximately 100 kilometers in length. The island's terrain consists of limestone uplands in the southern and northern regions and a central plain. The island's highest point reaches approximately 500 meters in the northern forested region. The Ryukyu Kingdom governed the islands from 1429 until Japan annexed the kingdom in 1879, establishing Okinawa Prefecture. The islands formed a trade network connecting China, Japan, Korea, and Southeast Asian regions. The Battle of Okinawa in 1945 killed approximately 12,000 American military personnel, approximately 94,000 Japanese military personnel, and approximately 100,000 Okinawan civilians. American military administration continued until 1972 when the United States returned the islands to Japanese sovereignty. American military bases currently occupy approximately 18 percent of Okinawa Island's land area. Futenma Marine Corps Air Station occupies approximately 480 hectares in Ginowan city, surrounded by residential areas. The Kadena Air Base, operated by the U.S. Air Force, covers approximately 2,000 hectares and contains runways extending 3,700 meters.
The Japanese archipelago extends approximately 3,000 kilometers from northeast to southwest. The four main islands — Honshu, Hokkaido, Kyushu, and Shikoku — comprise approximately 97 percent of Japan's land area of 377,975 square kilometers. Honshu, the largest island, covers approximately 227,960 square kilometers and extends approximately 1,300 kilometers. Hokkaido covers approximately 83,424 square kilometers. Kyushu covers approximately 36,782 square kilometers. Shikoku covers approximately 18,297 square kilometers. Approximately 14,125 smaller islands surround the main four, though only approximately 430 sustain permanent populations. The archipelago sits along the Pacific Ring of Fire where the Pacific Plate, Philippine Sea Plate, and Eurasian Plate interact. The Pacific Plate subducts beneath the Eurasian Plate along the Japan Trench, which reaches depths exceeding 8,000 meters approximately 200 kilometers east of Honshu. This subduction generates earthquakes including the magnitude 9.0 Tohoku earthquake on March 11, 2011. That earthquake occurred at a depth of approximately 30 kilometers beneath the seafloor. The resulting tsunami reached heights exceeding 40 meters along sections of the Sanriku coast. The earthquake released energy equivalent to approximately 480 megatons of TNT. Approximately 15,899 people died and 2,525 remain missing according to National Police Agency figures through 2021.