Umihotaru

photo by Kentagon · CC BY-SA 3.0

photo by Dandy1022 · CC BY-SA 4.0

An island halfway along the Aqua-Line, between the longest bridge and the longest undersea tunnel in Japan.

The artificial island, 100 metres by 650, joins the two halves of the Tokyo Bay Aqua-Line, opened on 18 December 1997: towards Kawasaki a 9,607-metre tunnel goes down to about 60 metres below sea level (the longest undersea stretch in Japan, though not the longest road tunnel overall); towards Kisarazu a 4,384-metre bridge, the longest bridge in the country. On floors 4 and 5 are the observation deck, shops, restaurants and a foot onsen; below, three floors of car park.

The tunnel was chosen on the Kawasaki side because the waters there are deep and used by large ships, and a bridge would have exceeded the height limit imposed by the nearby Haneda Airport; on the Kisarazu side, with less shipping, it was possible to build above the water. The junction island, created as a piece of engineering, is today also the only service area in Japan surrounded by sea on every side.

ℹ️ Car park and service area open 24 hours. Shops, restaurants and the foot onsen have their own hours, not read in this pass.

🚉 Sea firefly · in front of the station

Sources: pref.chiba.lg.jp · ja.wikipedia.org

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