Tower of Wind in Tokyo www.amusingplanet.com

Located just to the southeast of Tokyo's Haneda airport, in the middle of the ocean, is a rather interesting structure.
The truth, however, is very mundane – it is just a ventilation shaft for the Tokyo Bay Aqualine – an undersea tunnel that lies approximately 40 meters below.
Tokyo Bay Aqualine is the fourth-longest underwater, 9.6 kilometers long that runs from Yokohama to Chiba under the Tokyo Bay.
The attractive monolith houses the tunnel’s intake and exhaust ventilation system and also marks the midway point of the undersea tunnel.
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