I've just finished the game's main story, and along the way I did all the viewpoints and found all the Codex pages as I went along.
Occasionally you get a bit stuck and have to wait for the story to enable new locations or techniques.
I found the statue podiums in the Villa but didn't know what they were about. I assumed someone would show me the first one or a map or something as an explanation for what to do.
I now know they are hidden in the Villa, but how was I supposed to find that out?
Like with the feathers, the little bro asks you to get some and then Maria wants them in the box... Who tells you about the statues?