SA's mother's place.
SA's grandmother's place.
Any property owned by SA's family.
Any known hangouts of SA, especially his 'video shoot' spots.
Places in the area SA lived in the past, if not included above.
I would look at all these places, with particular focus on anything that had a storm cellar or shed that was rarely used.
Living in a rural area, sometimes there are hangouts that are really out in the middle of nowhere. A friend who grew up here where I live took me out to a cemetery at least 7 miles down a dirt road, with a 'town' nearby of maybe 12 scattered trailors and run-down homes. This is where they used to go as teens to hang out and drink. The young adults today don't go there anymore, apparently they've found a new place. So also, anything like that, especially if it has fallen out of favor in the last few years.
We're thinking along the same lines. If SA harmed her, that is. I keep thinking about where Caylee Anthony's remains were found - KC's childhood pet cemetery.