More millennia roll by. The sun grows hotter, the clouds dissipate, replaced by a large and fierce sun, the grass dies, the oceans start to recede from evaporation, no more human visitors, it is no longer hospitable for them to live on Earth as the sun is expanding. My plastic body starts to melt during the hot days, baking in the oven of the tomb.
Some pilgrims notice and there is some debate that allowing this to continue may destroy many valuable historic or archaeological sites, since plastics and water make a large part of them.
More time flows by and it seems the sun is getting fainter, I can see lights on a nearby mountainside, and we shift into twilight and then constant starlight. The Earth is being moved into a higher orbit. What is left of the oceans freezes over.
The mountainside lights grow and that civilization expand downwards into the crust. Gaia is still warm within, and interstellar space is cold, so they gather their energy geothermally.
At some point I watch and a small meteorite comes my way, as I wonder if this will ever end. It destroys a corner of the tomb.
A black cloak of some kind covers my temple to protect it from the interstellar journey. My visitors come out of a tunnel that emerges in the base of the temple.
After quite some time a new solar system comes into view, this time a red dwarf star. There is much rejoicing at the light after so long in interstellar space.
The original Sol is a red giant and reaching its final stages of life.