You're right. I didn't notice the little stone building at first.
We know there's at least one body buried there already.
Watching the opening the first time, I wondered why the camera paused here:
Now I know that hump is where Nacho is buried.
“Now I know that hump is where Nacho is buried.”
Oh, yeah. That makes sense. Good catch.
That other body would be the driver of the truck Mike stopped on the road? (I think.)