Mission 4: Under Watch | Secret Doors DMC: Devil May Cry Guide

DOOR 1/2 (required Copper Key; bonus mission Simple Traversal) - Door is in a small room next to the second camera. To get there you need to destroy grapevine with Osiris or Aquila.

DOOR 2/2 (required Argent Key; bonus mission Flawless Conquest) - Door is on a high balcony behind the second camera. You need to use Angel Boost and Angel Lift.