There are many theories as to the origins of the name Banyamine. The most widely accepted of those states that in the feudal age of Japan, the Satsuma Domain (which comprised most of what is now present-day Kagoshima Prefecture, centered on the Satsuma Peninsula) had a tsunami lookout called such as this site.
At the onset of America and Japan’s wartime involvement in 1941 (Shōwa 16), an air defense lookout was built here in order to monitor the comings and goings of aircraft in the vicinity.
While there is nothing left of the actual building, a square impression remains visible in the ground, thus giving us an idea the size of the lookout. If you close your eyes, you can envision the tense, wartime atmosphere: listening with sharp ears for approaching aircraft by using an acoustic mirror, keeping watch for the worst-case scenario of an approaching bomber, etc… May peace prevail on this Earth.