Thinking about archaeology in Star Wars...
So the Star Wars galaxy has some old civilizations. By that, I mean really, really old. Consider that the Empire of Xim existed around 25,000 BBY when it went to war with the Hutts. This means that both of those civilizations had high-tech building materials way back then. We have no structures on Earth that are comparable, so how long would cities built of such materials last (assuming they were made to resist the elements of wherever they were built)?
Coruscant shows us that the old stuff just get built over, but if it is, it is obviously still standing and structurally sound. Do we get ghost towns like those found in the western US, but instead of 150 years of slowly decaying dried wood they're built out of materials that last millennia? If so, there are likely to be ancient structures all over the place retrofitted again and again over the ages.
Just some rambling thoughts.