Japan has a quite a few interesting man-made structures. For Today’s Japan photo, we will take a look at the magnificent Umihotaru 海ほたる.
Here’s a little more information on the Umihotaru [海ほたる]:
Umihotaru [海ほたる], literary means the firefly of sea, is the artificial island in the middle of Tokyo Bay.
It is the resting area located in the middle of Tokyo Bay Aqua-Line [東京湾アクアライン]. Umi-Hotaru is very popular night-scene spot where you can enjoy the great city light of Tokyo. Umihotaru itself also have many light-up demonstrations. For example, there is firefly light up at the north-west side of the island. There are many restaurants, gift shops and other entertainment facilities.
And here’s a youtube video tour of the Umihotaru:
Even though I never watched Working!! myself (wished I did), I... – 
Its an island? is it connected to the mainland or how do you get there?
Its the connecting point between the bridge and a long underwater tunnel. The unique-tunnel bridge is called Tokyo Bay Aqua-Line, and Umi-Hotaru is in-between.
It’s this the structure shown on the Cutie Honey live action movie?
I think it is a man made island. I believe only way to get there is to cross the bridge.
insane…i never knew this place exsisted…yes…directions please
cool. i nv realised it is man made until i read ur post
I want to visit this place when I go to Japan!