Kasumigaura Bridge, Road bridge in Kasumigaura and Namegata, Ibaraki Prefecture, Japan

Kasumigaura Bridge is a steel continuous plate-girder road bridge on National Route 354, crossing the western basin of Lake Kasumigaura between Tabuse in Kasumigaura city and Tamatsukuri-Ko in Namegata city, Ibaraki Prefecture. It is 1,015.6 m long and 11.5 m wide, with two traffic lanes and a 2.5 m walkway on one side. Its deck rests on 27 piers set in the lake bed.

A bridge over the lake was first proposed in 1978, after a planned reclamation dike between Dejima and Tamatsukuri was cancelled; the prefecture and local groups pushed the idea forward, and construction began in 1983. The 1,015.6 m steel continuous plate girder bridge opened on 3 March 1987 as a toll road, became part of National Route 354 in 1993, and was made free on 1 November 2005. Until then a prefectural ferry, the Dejima Maru, had linked Kashiwazaki and Hama since 1965.

The bridge connects two sides of Lake Kasumigaura and is part of daily life for people living along its shores. Driving or walking across it offers open views over the water, which locals often pause to take in at dusk.

Crossing the bridge on weekdays outside of rush hours makes for a smoother trip with less traffic. Wind can pick up strongly over the open water, so take care when driving during stormy or windy weather.

Lake Kasumigaura is one of the largest lakes in Japan, which means that crossing the bridge can feel like driving over open sea even though the ocean is far away. On misty mornings, both shores often disappear in the haze and the bridge seems to lead into nothing.