Usui Bridge

The Usui Bridge (碓氷橋), also known as the Meganebashi (眼鏡橋, "Spectacles Bridge"), is a historic bridge located in the Usui Pass area, specifically in what is now part of Annaka, Gunma Prefecture, Japan. It is a significant example of Meiji-era infrastructure and engineering.

Constructed between 1891 and 1893 as part of the Shin'etsu Main Line railway, the bridge was built to overcome the steep gradients and challenging terrain of the Usui Pass, a historically difficult mountain crossing. The Shin'etsu Main Line was vital for connecting Tokyo with regions to the northwest, including Nagano.

The Usui Bridge is notable for its construction using brick arches. It consists of four arches, each with a span of 31 meters, giving it its distinctive "Spectacles Bridge" appearance. At the time of its completion, it was the largest brick bridge in Japan.

The original railway line using the Usui Bridge was abandoned in 1997 when a new, straighter route through a tunnel was opened for the Nagano Shinkansen (bullet train). The Usui Bridge, however, remains a preserved historical site.

Today, the Usui Bridge is a popular tourist attraction and a symbol of Japan's modernization during the Meiji period. Visitors can walk across the bridge and explore the surrounding area, which includes other remnants of the former railway line and the Usui Pass itself. The site provides insight into the engineering challenges faced and overcome during the development of Japan's railway network.