Woah, hold your rockets there, Captain Eager. Where did I ever say that the sarcophagus would last 50 million years intact? Once again, you show that you are perfectly happy to assume what I am saying instead of reading what I actually say. Congratulations, you've successfully killed the strawman. Well, the whole oxydization process would seem to me to require oxygen. Peat bogs have been shown to preserve corpses excellently. Of course, it's another matter regarding how long the bog lasts. Yeah, Id guess that a small, extremely fragile eggshell that has had nothing done at all to protect it is much LESS likely to survive. But we've seen that a civilization that has advanced to the level where it can build rockets has also developed to the point where it can build sky scrapers. I know, I was being a bit overly picky about that, wasn't I? Just playing devil's advocate. Well, the only reason I ask is that you seem to be responding to points that I haven't been making. Would you care to explain WHY? Because I tend to think that evidence that a bone made a recovery that could only happen with help from advanced technology is evidence that the individual was treated with advanced technology. Do you think differently? Because you've been nothing but polite, have you? What would I count as evidence? Imagine that alien scientists came to Earth in 50 million years. What could they find they would give them cause to think, "About 50 million years ago, there was a technologically advanced civilization that spread across most of this planet." What would give them cause to think that? That is what I would consider evidence. If you somehow concluded that I meant buildings would survive intact when I never said anything of the sort, then you obviously can't comprehend things very well. Don't blame me for implying when it is you making inferences. See those parts I highlighted? How you can read that and then conclude that I meant that buildings will remain intact over millions of years is absolutely beyind me. So, I conclude that you read what you THINK I am writing and reply to what you THINK I said. Your argument that "They're just rocks and they'll erode" would be a lot more convincing if we didn't have any rocks older than 50 million years. And don't tell me that those are igneous rocks. We have plenty of sedimentary rocks that are older than 50 million years too. After all, we only ever find fossils in sedimentary rocks. You seem to be going from the assumption that ALL things underground are subject to things that will destroy them. This is not true. Traces that are left of the pyramids could be the large flat areas of rock that they are built on showing signs of having a large, square-based object on top of them, that, when viewed in relation to the path of the nearby river (yes, rivers leave traces, it's how we get dinosaur footprints, so don't tell me it doesn't happen), match up to the position of the stars in Orion's belt in relation to the Milky Way. And don't start on how the stars will be in different positions in 50 million years. Any alien scientists who come along in 50 million years will certainly be able to piece together what position the stars were in. And you do the same.