How to get all secret areas in Reunion at the Old Trellis
Secret area #1
The first secret area is inside the cave. You will get the objective ‘Open the door from inside the cave’. You can find the secret area on the left side of the lever near the wall.
Secret area #2
After coming out of the cave, you need to go right side and climb up to pull the lever to free others. You can find the secret area on a platform over the lever.