[RoosterRedux]

It certainly could be a sewage treatment tank.

But look at this photo from the air. You can make out letters written on it (I can make out an "N"). And what would be a walkway out to the drive platform on a sewage treatment tank appears to be a Masonic compass with the vertex at the very center of the circle.

[buffaloguy]

One of the pictures I saw of it made it look like a tank rather than a sundial.

It has two eyes and a mouth at the center.

[buffaloguy]

One of the pictures I saw of it made it look like a tank rather than a sundial.

It has two eyes and a mouth at the center.

[buffaloguy]

The image is stitched together as the shadow on the dial does not match the surrounding the shadows of the palms.

I wonder why there so many stitched photos of the island. It is only 72 acres.

[SERKIT]

But look at this photo from the air. You can make out letters written on it (I can make out an "N"). And what would be a walkway out to the drive platform on a sewage treatment tank appears to be a Masonic compass with the vertex at the very center of the circle.

Previous posts show that the little rectangle (white with ragged black outlines) are benches. This site looks ceremonial, otherwise, why would there be benches around a smelly sewage treatment plant?