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Chiba: Inubosaki Lighthouse Museum Illuminates History of Japan Coastal Beacon

The Yomiuri Shimbun
A huge Fresnel lens is seen at the Inubosaki Lighthouse Museum in Choshi, Chiba Prefecture.

CHOSHI, Chiba — Known for its reefs and frequent fog, Inubosaki cape is regarded as a perilous location for shipping. To help ameliorate potential danger, Inubosaki Lighthouse has been lighting up the sea and serving as a navigational beacon off the cape in Choshi, Chiba Prefecture, for more than 140 years.

The Yomiuri Shimbun
Inubosaki Lighthouse is one of only 16 climbable lighthouses in Japan. The light from the lighthouse can reach up to 36 kilometers away.

Inubosaki Lighthouse Museum sits across from the tall, white beacon and details its fascinating history.

A giant Fresnel lens — similar to that used in Inubosaki Lighthouse — dominates the center of the museum. According to Tokyo-based lighthouse-research body Tokokai, the lens was previously used in Okinoshima Lighthouse in Fukuoka Prefecture. The concentric rings of the lens — named for its developer, Augustin-Jean Fresnel — are stacked from the center in a geometric pattern. The museum also displays many other items, including a lens of the now-defunct Tokyo Light Beacon, which once helped illuminate Tokyo Bay.

The Fresnel lens in Inubosaki Lighthouse collects and redirects light from light bulbs to locations up to more than 30 kilometers away. The light has a brightness of 1.1 million candela — equivalent to the light emitted by 1.1 million candles.

“It’s like a giant eye that watches over the sea,” said Hiromi Urashima, a former lighthouse keeper at the Choshi Coast Guard Office.

The Yomiuri Shimbun
A Fresnel lens used in Inubosaki Lighthouse

The lighthouse was built in 1874 by a British engineer invited from Britain by the Meiji-era government. The tower, which comprises some 190,000 white bricks, became a symbol of the local community, while helping ensure safety at sea.

Urashima, 69, explained that a nearby building previously served as a fog signal station. Fog tends to form off the Choshi coast due to temperature differences between the sea surface and the atmosphere. When visibility was poor, a lighthouse keeper would sound a foghorn to inform ships of the land’s location. The foghorn was said to have sounded akin to a bovine “moo,” and was thus dubbed “Inubo’s cow.”

“It was so loud that I thought rust would fall off the building,” Urashima recalled.

Foghorn usage has declined with the spread of global positioning system (GPS) devices and other technologies; lighthouse numbers have been dwindling, too. However, for many mariners, the glow from a lighthouse remains special, as it helps them navigate with peace of mind.

The Yomiuri Shimbun
The inside of a former fog signal station in Choshi, Chiba Prefecture

“Even with the development of modern equipment, I still feel a familiar sense of security when a lighthouse illuminates the darkness,” Urashima said. “I hope such lights continue to shine.”

Inubosaki Lighthouse Museum

The Yomiuri Shimbun

Inubosaki Lighthouse Museum opened in 2002 and details the history of Inubosaki Lighthouse and its role as a navigational beacon. The lighthouse and a former fog signal station were designated as Important Cultural Properties in 2020 by the government.

Address: 9576 Inubosaki, Choshi, Chiba Prefecture

Hours: 8:30 a.m. to 5 p.m. (from March to September). Open daily but closed in cases of stormy weather and other circumstances.

Admission: ¥300, including a visit to the lighthouse; free for elementary school students and younger.