Go to the coordinates in the eye sockets, and it takes you to another landmark with coordinates.

Didn't seem to work for me.

The coordinates that are indicated in the landmarks are a bit hard to read sometimes, and you have to piece them together. The skull in New York is pointing to: (-15.36, 15.90). After searching for that location, zoom in on the green arrow, and you should see a piece of ham that is pointing to: (-21.53, 46.05)

The coordinates at the sword that comes next are also ambiguous. You have to infer that the 9 in the handle is indicating that the first number is 9.81.

Oh, I see - thank you!

There's a similar one in Amsterdam.

Seems to be the only "special" icon in NL though.