This post took me into a long search of the area, which, by the way, was fascinating. It is interesting to see all the articles, pictures, and information on the lighthouse and radar station. The fort? Nada!
No matter how I asked for the Sandiaojiao Fort, Taiwans extreme East Point, San Deigo... Magang fishing village, Blue Greece... Nothing. I am not sure I have ever come across that. Even the pictures I have of the area are devoid of it. Ha! Yet, you have proof positive.
What are they hiding??? Just kidding! I just found it so funny. Google doesn't know everything and good think you marked it!
Lots of these places in Taiwan don't have English coverage on the internet as English is still not that widely used even though they've been talking for years to officially make English the second language. Glad I can add them on the blockchain 😃