It seems clear that living things outlast just about any other structures in the world. Therefore the only things we are likely to create are what we grow organically. Everything we have built over the last few millennia is unlikely to be around for much more than a few thousand years from now (if that). If we want to make things which will last longer than that we need to learn how to save our signature in the genes of living things. It seems likely that the current production of inorganic machines, buildings etc. will be replaced over the next few centuries by processes of growing what we need from seed. A future city would then be like a forest - able to adapt and survive the ravages of time. If we want to preserve our knowledge then any inorganic storage is going wear out - we need to encode it into a DNA like self-replicating structure to be extracted by future generations or future species.