2nd Sunken Church: East Wing; The First Secret
When you first enter run through the hall and on your left is a broken wall leading to another room, but don't go in there just yet. Keep running down the hall and you will turn left the rest of the way down the stairs. On your left is a door. It doesn't open so don't even try it. On the right hand side, however, is an abnormal looking wall. Kick it down and in it lies your first secret.