The Sado Island Gold Mine was once the largest gold mine in Japan. Over a span of nearly 400 years, the mine produced 78 metric tons of gold, an amount worth billions of US dollars today. By the time operations were halted in 1989, it had 400 kilometers of mine tunnels—enough to stretch from Sado to Tokyo.

The Sōdayū Mining Tunnel is one of the oldest parts of the mine. A 2-kilometer-long gold vein was discovered in Aikawa in 1596, triggering a gold rush that drew tens of thousands of miners and other workers to the island. Today, the mine tunnel has dioramas showing how the miners worked and lived.

Keeping water out of the mine was a constant struggle. Workers extracted groundwater from the tunnels using screw pumps (also called “Archimedes screws”). The Greek philosopher Archimedes is credited with the invention of these pumps, and this crucial technology is thought to have been imported from Europe. The pumps were used at Sado Island Gold Mine starting in the midseventeenth century.

Screw pump operators were well paid, and many were recruited at a young age from surrounding farms. Although the large pumps improved the process of draining the tunnels, they could not be used in all parts of the mine. The mechanism behind the Archimedes screw did not function at extreme vertical angles, so in tight tunnels, flood fighters had to make do with buckets and pulleys.

Timberers performed a vital role. In addition to making supports to shore up the tunnels, they built wooden platforms, assembled water troughs, and created stepped inclines. They also built the simple wooden stepladders that were used to climb in and out of the mines. These ladders were made by cutting wedge-shaped steps into single logs.

The job of timbering was called yamadome, meaning “holding up the mountain.” Timberers had to be highly skilled to create sturdy supports that fit the rocky, uneven walls of the mine. Notice the helmets made from tightly twisted paper. This protective headgear was given to technical specialists such as timberers, but other workers had to go bareheaded.

Tasks such as carrying ore and tools, assisting senior miners, and filling oil lamps were carried out by apprentices. Still others worked under blacksmiths or assisted in shoring up the mine. Boys could become mine apprentices starting at age 15, and a special foreman was assigned to manage them. Other foremen were stationed at the mine entrances to monitor workers as they came and went. Their watchful eyes kept anyone from walking off with tools or gold, and their records served as the basis for calculating wages.

Until the adoption of electric lighting, miners worked by the light of lamps, candles, or torches. The smoke and soot in the air often mixed with stone dust, making it difficult to breathe. To counteract this, a ventilation tunnel was added to circulate fresh air. Some tunnels were even fitted with handcranked extraction fans modeled after the rotary blades in rice-threshing machines.

A range of different fuels were used over the mine’s centuries of history, including pine resin, vegetable oil, and fish oil. The fuel was burned in iron-handled lamps that could be carried or hung from hooks on the walls. In other cases, miners carried torches wrapped in thinly shaved cypress bark and soaked in oil.

The gold ore was excavated by skilled specialists called kanahori-daiku. They worked short, fourhour shifts in groups of two or three and took meal breaks in the tunnels. These important workers were paid especially well, and they were known as big spenders who wore the latest fashions and hair styles from the faraway capital of Edo.

It is said that the kanahori-daiku contributed to the origin of a local folk dance called ondeko, or “deity drumming.” Nineteenth-century records of the Aikawa festival recount that the miners donned masks and beat their taiko drums as if they were striking their chisels with hammers. A version of this performance is held each year in mid-October.

By the mid-eighteenth century, the mine tunnels stretched deep into the earth. The scale of the operation made screw pumps prohibitively expensive, so groundwater had to be removed using buckets. Beginning around 1778, the government in Edo began rounding up refugees and vagrants in urban areas and sending them to perform this drainage work. They were provided with wages as well as food, clothing, and lodging, and after a set period, they were allowed to return home or settle permanently on the island.

In total, some 1,900 people were sent to Sado to work draining the mine tunnels. Of these, 28 were killed in 1853, when a fire broke out in the mine. A memorial service for them is held each April.

The gold in the Sodayū Mining Tunnels was excavated from hard, quartz-rich rock. Miners excavated the ore using hammers and chisels, which was very slow work. A pair of miners digging for 8 hours made only around 10 centimeters of progress, and their chisels had to be replaced two days.

The tools were resharpened by blacksmiths stationed outside the mine. These specialists also made and repaired other tools, such as the pliers that miners used to hold their chisels steady. Making new tools and maintaining old ones was never-ending work, and large quantities of iron was regularly imported from the mainland to supply the blacksmiths' workshops.

Officials from the Sado magistrate’s office did the work of surveying and planning the tunnel excavation. Prospectors called yamashi located veins of gold, and highly trained engineers designed the mine tunnels. A well-planned mine had tunnels for ore extraction, ventilation, and drainage.

Many of the tools and calculation methods used at the Sado Island Gold Mine would be familiar to mine surveyors today. Surveyors working on Sado used the latest European methods, which had been introduced by Dutch merchants. In the 1690s, the renowned surveyor Shizuno Yoemon is said to have used techniques learned from the Dutch when he planned the Minamizawa Drainage Tunnel. The kilometer-long tunnel was dug in three sections simultaneously, and Shizuno’s plans were so precise that the sections, when joined, lined up almost perfectly.

The Dōyū Mining Tunnel was first excavated in 1899. Unlike the much older Sōdayū Mining Tunnel, which was dug by hand, this tunnel was excavated by blasting. One clue to the mine’s age is the presence of cylindrical holes here and there along the walls. These were drilled for sticks of dynamite.

In 1896, the government sold Sado Island Gold Mine to Mitsubishi Gōshi Kaisha (now the Mitsubishi Corporation), and the Dōyū Tunnel was completed three years later. Unlike the older tunnels, which slope and wind through the mountain, barely wide enough for a single person, the newer Dōyū Tunnel is wide and level to accommodate modern, rail-mounted minecarts for transporting large amounts of ore.

The temperature in the tunnels is a chilly 10 degrees Celsius throughout the year, a perfect environment for storing sake. Even today, producers of sake and shōchū spirits on Sado Island use the tunnel as a place to age their products for several years. When the mine was still active, miners supposedly stored watermelons in the mine as a cool, sweet snack to eat between shifts.

Before the age of modern mining equipment, workers carried ore out of the tunnels in large bags made from straw. That changed with the introduction of rail-mounted minecarts in the late nineteenth century. The minecarts ran on tracks that led to the aboveground processing plant, where the ore was crushed.

The first minecarts were pulled by men or horses. Small, gasoline-powered locomotives came into use in 1932, followed by electric locomotives in 1939. Some sections of the tunnels were only wide enough for one set of tracks. To prevent collisions between carts traveling in opposite directions, the operators signaled each other with a system of red and green lights. The lights were operated by lever switches installed at the points where the tracks narrowed.

The gold rush at Sado Island Gold Mine began in 1596, after three prospectors discovered a rich vein of gold in Aikawa. Within a few decades, miners using nothing more than chisels and hammers had removed enough rock to create a large, V-shaped gouge in the mountain. This unique feature is called the Dōyū no Warito, or “Dōyū Open Site.” It has become a symbol of Sado Island Gold Mine and the monumental scale of the mining work that went on there. At 30 meters across and more than 70 meters deep, it is one of the largest such sites in the world.

The arrival of new technologies greatly improved the mining process. One such technology was dynamite, which was introduced from England. Miners used dynamite to blast rock from the mountainside. The blasted rock (or “muck”) fell down through the open gap into the tunnels, where it was loaded onto minecarts.

Takatō Jinja Shrine honors the spirit of Ōshima Takatō (1826–1901), known as the father of modern Japanese mining. Ōshima served as director of the Sado Mining Bureau in the 1880s and significantly expanded and modernized the mine. It was Ōshima who reopened excavation of the Dōyū Open Site using dynamite and ushered in a new wave of activity. New facilities built under his leadership include the Takatō Shaft, an ore processing plant, and shipping infrastructure at Ōma Port.

Takatō Jinja Shrine is a subsidiary of Ōyamazumi Jinja Shrine, which was founded in 1605 by the first magistrate of Sado. That original shrine was built to bring prosperity to the mines, and Ōshima himself worked hard to achieve the same goal. A Shinto ritual is held at Takatō Shrine every July to pray for safety at the mine.

This 659-meter shaft is the longest vertical access tunnel at Sado Island Gold Mine. It opened in 1887 and is named for Ōshima Takatō, the pioneering mine director who oversaw its construction. Vertical shafts like these were used to efficiently access the horizontal mining tunnels far beneath the earth.

The Takatō Shaft was equipped with a powerful 180-horsepower hoist that took workers and supplies down into mine tunnels and lifted ore up to the surface. At its deepest point, the Takatō Shaft stretched 659 meters below ground, more than twice the height of the Eiffel Tower. A huge steel winch tower, or “headframe,” once stood over the entrance, but it was replaced with a smaller one in 1952.

The minecarts that hauled ore and miners through the tunnels were powered by electric locomotives. At the end of each day, the fleet of battery-powered locomotives was hauled to the surface for recharging in this building. The structure also served as a repair shop for carts, pneumatic drills, headlamps, and other mining equipment. The machinery displayed there dates mostly from between 1935 and 1944, and much of it remained in use until the mine ceased operation in 1989.