Changing the scene origin

I’m going through a Hello World type tutorial and ran across this note:

When we initially create a terrain in
Unity, the origin of that terrain is
in a corner. You can change the
scene origin to (0,0,0)
so that it
is in the middle of the terrain. This
can make it easier to manage the

I can see all of the position settings on game objects, but I’m not really sure what he means by the scene origin. I’m sure I’m missing something obvious, but where can this be set?

ok got it. The next step re: height tool and flatten. when you click “flatten” it sets origin to 0,0,0.