[Bubba Ho-Tep]

Okay. But does the rock stay the same for all eternity? And how did the ancients get their paint to last so long?

They're 300-700 years old, hardly "all eternity." Barely a blip, geologically. And it looks like they're mostly protected from the sun and other elements by overhangs.

[cripplecreek]

Virtually every ancient monument connected to celestial events are still accurate to within a degree or two. After all, even things 5000 years old are very recent on the time scale of the earth.

[WayneS]

Do the overhangs protect them from earthquakes?