KOBE, Japan >> A tunnel might seem like a most unlikely spot for a concert, but the Minatogawa Zuido tunnel in Kobe has become just that — a popular place for jazz bands, brass bands and choruses to perform. It was originally built to reroute the Minatogawa river that flows through Kobe, but has now taken on a completely new role.

Various free events are held every month at the tunnel, which is managed by the Hyogo prefectural government.

About 180 people enjoyed a recent concert by a local chorus of students, their clear voices resounding throughout the dimly lit tunnel.

“Their singing voices came down from the ceiling, and I felt like I was being enveloped in them,” said Chiaki Shimizu, who visited Nara Prefecture.

“The voices resonated in a unique way, and our singing felt good,” said Kazuki Matsumoto, a group leader with the chorus.

The tunnel was built in 1901 and is said to have been the first modern river tunnel in the country. It was constructed to address the Minatogawa river, which flowed south from Mt. Rokko through Kobe city.

Prior to the tunnel, the river was prone to flooding and held up traffic between east and west because the river bed was higher than ground level. The situation also caused a great deal of earth and sand to flow from the mountains into Kobe Port, making the port shallow and preventing large ships from docking.

In 1897, some 30 local businessmen established a company to address the river. They removed the embankments, cut through the mountain and began work to reroute the river. In those days, immediately following the Sino-Japanese War (1894-1895), digging equipment that could get the job done efficiently did not yet exist. Construction was difficult, a job handled with chisels and pickaxes.

The completed tunnel stretched about 650 yards, with a width of about 24 feet and a height of 25 feet. More than 4 million bricks were used on the side walls and arched ceiling, and its floor was covered with granite to prevent erosion from the flowing water.

With the issues of the river alleviated, the surrounding area developed and flourished, becoming downtown Kobe’s busiest streets, lined with movie houses and theaters.

“Local businessmen spent about 4 billion yen in today’s money and built the foundation for the prosperity of the city,” said Ryosaku Sasaki, a former civil engineer for the Hyogo prefectural government and vice chairman of the Minatogawa Zuido preservation citizen group. “(We aren’t aware of any) other example of accomplishing such a big civil engineering project through private efforts alone.”

In the more recent past, the tunnel drew attention after the Great Hanshin Earthquake in January 1995. Until then it was called the Mt. Ege tunnel and was hardly known to the public.

Restoration work revealed the tunnel’s official name: A nameplate discovered on a wall said “Minatogawa Zuido.”

In 2000, a new river tunnel was completed, retiring Minatogawa Zuido. But the prefecture decided to preserve the old tunnel for future generations, improving its lighting facilities and passageways.

In fact, it was selected in 2011 as a civil engineering heritage site by the Japan Society of Civil Engineers, which encourages the preservation and utilization of iconic structures. Last year, a council of the Cultural Affairs Agency proposed that the tunnel be registered a cultural property of Japan.

Amid the accolades, the citizen group continues to organize concerts, memorial events and exhibitions on site. In fact, it receives many inquiries from artists hoping to perform there. And in today’s social media climate, the tunnel has been deemed “Instagrammable,” drawing visitors from outside Kobe.

“I feel (warmth) here,” said Megumi Takaya, who visited a photo exhibit there.

No doubt, the huge underground space will continue to draw in visitors, leaving them with a dose of history and culture that nourishes the soul.

Minatogawa Zuido is a 10-minute walk from Minatogawa Koen Station on the Kobe municipal subway, or from Minatogawa Station on the Kobe Electric Railway line. It is open to the public once or twice a month. For inquiries, contact the Kobe civil engineering office at 011-81-78- 737-2382.