Spiral Walk (渦の道) is a sky walk under Onaruto Bridge, Tokushima Prefecture. The altitude of the pass is 45m above the sea level. It is a pass to enjoy Naruto Spiral. Naruto Spiral is the most famous phenomenon in Tokushima. Because of the great tideal current at Naruto Strait, it create large spirals at the strait. Spiral Walk access to the top of the spiral. There are see through window on the floor to enjoy the spiral.
Tourist Info.
There are parking and restroom.
Admission: 500 yen.
Time: 9:00 to 18:00 (10:00 to 17:00 from Oct. to Feb.) GW and August is 8:00 to 19:00.
Access
0. at Tokushima Station.
1. use JR Naruto Line to Naruto.
2. use local bus to Narutokoen.
500 JPY
1 hr.
New Wave Samurai Movie. 
映画好き集まれ！ 
Uzunomichi, or Spiral Walk, is a 450m long sky walk located under Onaruto Bridge. It is 45m high from the see and has observatories to see Naruto Spiral.
It has also a great view of Seto Inland Sea and Pacific Ocean.
The best time to see the spiral is 2 hours between the tide.
Official Web: http://www.uzunomichi.jp/