Secret Japanese Imperial Navy Base.

PBS airs a series called 'Nazi Megaweapons' - (terrible title, interesting content!) Last night they covered several Japanese suicide weapons, one of which was the 'Kaiten' human guided torpedo. Here is the top secret manufacturing, training and deployment base. The link below is to a comprehensive article on this manned torpedo. The weapons were transported through the tunnel to a jetty where they could be lowered into the sea. From here they were towed to deeper waters for training. A typical training session might be a circumnavigation of the island. Training losses were very high. The 'Kaiten' were taken from here into combat on the decks of conventional submarines. The weapon experienced very limited success.

en.wikipedia.org/wiki/Kaiten

Secret Imperial Navy Base..kmz (1.68 KB)

Interesting! There are several photos in the photo layer of things you have placemarked.

Thanks, Washi - I had intended to point this out but forgot! Now you have done it for me.  Larry