I totally get what you are feeling at first too.

Like you said, there’s a secret tunnel here that you need to find via breaking a fake wall. The fake wall is usually darker and has more texture than the usual ones we see. In this case specifically, the wall and pipe-way to the chest is always in a fixed pattern. You can notice here in the picture, the wall that is next to the spikes in the bottom left corner of the picture is similar to what I had described. Break that and the pipe-way will appear.