Shadow of the Colossus: all secrets, hidden modes and easter eggs

There's quite a lot hidden around the world of Shadow of the Colossus.

The mystery of the Hidden Door in Demon's Souls Remake - solved by Distortion2 — GG Souls

Shadow of the Colossus: all secrets, hidden modes and easter eggs

Has anyone already discovered this? Is it a secret room? Maybe the bluepoint easter egg? : r/ShadowoftheColossus

Shadow of the Colossus Easter Eggs (PS4) - Shadow of the Colossus and ICO Guide - IGN

Shadow of the Colossus (PS4): How To Find The Secret Last Guardian Easter Egg Cave - Gameranx

Shadow of the Colossus (PS4): All Bonus Unlockables

Shadow of the Colossus Version Differences - Shadow of the Colossus and ICO Guide - IGN

Shadow of the Colossus (PS4): All Bonus Unlockables

The last secret of Shadow of the Colossus. The most obscure secrets in video games

Shadow of the Colossus Hidden Coins (PS4) - Shadow of the Colossus and ICO Guide - IGN

A really cool Shadow of The Colossus easter egg in Iki Island. Was extra special to me because I just platinumed SOTC 4 days ago. : r/ghostoftsushima

Shadow of the Colossus - Photo Mode Gameplay Walkthrough