In reading up a little on the fateful trip of Amelia Earhart, I starting looking around the minuscule little island where she'd hoped to make a refueling stop, Howland Island:
Quite a bit south and slightly east, in the middle of the Phoenix Islands, I discovered these:
I'm sorry, but I find it extremely unlikely that two "structures," one seemingly a perfect square, the other a perfect rectangle, oriented in exactly the same direction, could be formed by natural causes. I Googled and Googled and Googled, and I could find absolutely nothing about these things at all, not even half-baked Lost-City-of-Atlantis-style mythological theories. Finally I just got so frustrated that I gave up. What are those things? If you ask me, they look very much like temples.