Kawazu-Nanadaru Loop Bridge, Japan ...This bridge is one of its own kinds with two spirals. Each spiral is 1.1 KM and 80 meter diameter. The terrain where this bridge is situated is mountainous and the only way to enter the mountainside is this bridge. Other than this bridge it is too steep for any other solution. This bridge was built in 1981. People from Tokyo take this route on the weekends to enter the resort situated in the mountains.